PENCOYD UC-NRLF AND STEEI WILEY & SONS 1 LIBRARY UNIVERSITY OF CALIFORNIA. Received .-*^rK><**<*& 188 6. Accessions No.^?'*-*- Shelf fib. e*- -umVVff WROUGHT IRON AND -STEEL IN CONSTRUCTION. CONVENIENT RULES, FORMULAE, AND TABLES FOR THB STRENGTH OF WROUGHT IRON SHAPES USED AS BEAMS, STRUTS, SHAFTS, ETC., MANUFAC- TURED BY THE PENCOYD IRON WORKS. SECOND EDITION, REVISED AND ENLARGED. THE. uim SRSITT >RK. JOHN WILEY & SONS, 15 ASTOE PLACE, 1885. COPYRIGHT, 1884, BT A. & P. ROBERTS & CO. PREFACE. To Engineers and Builders in Iron and Steel this volume is presented, with the hope that it may be of assistance to them in their daily labors, and afford information upon some points which have not heretofore been put in published form. It has been the aim of the author to eliminate as far as possible mat- ters of theory from statements of facts, that, where conflict of opinion may arise, each one may draw his own conclusions. It was considered advisable to treat only of subjects relating to Iron and Steel, referring to any of the numerous engineers' pocket-books for information upon outside matters. As far as possible, doubtful points were corroborated by ex- periments, and especially Ihe' article upon "Struts " is based upon the results of several hundred carefully conducted experi- ments at Pencoyd, for more detailed information concerning which we would refer to two papers by Mr. Jas. Christie, pub- lished in the Transactions of the American Society of Civil En- gineers, entitled, " Experiments on the Strength of Wrought Iron Struts," and, " The Strength and Elasticity of Structural Steel," wherein the above experiments are fully described. Hereafter should errors be detected by a more perfect knowledge of the physical properties of the materials treated of, we shall be glad to acknowledge the same, but now offer the following pages as the best results we are able to obtain from present practice. A. & P. ROBERTS & CO. PENCOTD, May, 1884. PREFACE TO SECOND EDITION. IN preparing the Second Edition for the press we have cor- rected some small errors occurring in various places in the first edition, which were discovered after its publication. A few new tables of weights of separators for beams, of bolts, nuts and rivets, which were deemed useful in architectural calculations, have been added. Some additional shapes are described, and several old sections of beams and channels changed to more effi- cient forms, by better distribution of material in the flanges. At the present writing we have no alterations to make in our conclusions in regard to steel, our experiments up to date seem- ing to confirm our results as then announced. A. & . ROBERTS & CO. PENCOYD, January, 1885. PKEFACE TO THIRD EDITION. MOKE than a year has elapsed since the publication of the first edition of this little volume, and we are now preparing a third for the press. A few new sections have been added and several errors overlooked in the earlier editions corrected, so that we believe very few, if any, now exist. Our conclusions in regard to struts, based upon Mr. Christie's experiments, have stood the test of publication and criticism, and we think at this day can be said to have more fully the stamp of authority than when first issued. We trust this Hand Book has and will continue to be of value to all who daily use wrought iron and steel in con- struction. A. & P. ROBERTS & CO. PEKCOYD, July, 1885. CONTENTS. PAGES TABLES OF DIMENSIONS 1-16 STRENGTH OF WROUGHT IRON 17-23 STRUCTURAL STEEL 24-31 STRENGTH OF IRON BEAMS 32-39 TABLES FOR I BEAMS 40-45 TABLES FOR CHANNEL BEAMS 46-49 TABLES FOR DECK BEAMS 50, 51 IRON FLOOR BEAMS 52-55 TABLES FOR FLOOR BEAMS 56-62 BEAMS SUPPORTING BRICK ARCHES AND WALLS 63-66 APPROXIMATE FORMULAE FOR BEAMS 67-77 BENDING MOMENTS AND DEFLECTIONS 78-81 BEAMS SUPPORTING IRREGULAR LOADS 82-84 BEAMS SUBJECT TO BENDING AND COM- PRESSION 84-87 ELEMENTS OF STRUCTURAL SHAPES 87-91 TABLES OF ELEMENTS 92-101 MOMENTS OF INERTIA 102-111 RADII OF GYRATION 112-113 ROLLED STRUTS 114-153 TABLES OF I BEAM STRUTS 124-134 " ANGLE " 138-140 " TEE " 142,143 " CHANNEL STRUTS 144-153 COLUMNS.. ..154-159 VI CONTENTS. PAGES EIVETS AND PINS 160-162 STRESSES IN FRAMED STRUCTURES 163-169 WROUGHT IRON SHAFTING 170-177 PROPERTIES OF CIRCLES 178-183 WEIGHT OF ROLLED IRON 184, 185 DECIMAL EQUIVALENTS FOR FRACTIONS 186 ILLUSTRATIONS For a full detail of the contents see Index. UNIVERSITY WKOUGHT IRON AND STEEL IN CONSTRUCTION. TABLES OF DIMENSIONS. THE following tables give the principal dimensions of the standard shapes of structural iron and steel rolled at Pencoyd. Further particulars of the sections will be found in the illus- trations at the end of the book. For beams and channels the least and greatest sections of each size are described in the preliminary tables. Any inter- mediate sectional areas between the maximum and minimum can be rolled, but the flanges remain unaltered, the web only being thickened. The weights per yard corresponding to increased web thicknesses are given in annexed tables. For angles, any thickness between the maximum and minimum can be rolled, corresponding weights for the principal intermediate thicknesses being given in the tables. The legs of angles increase slightly in width as the thickness is increased. This renders the actual weights corresponding to given thickness somewhat uncertain. Therefore either the de- sired thickness or weight per yard should be specified, but not both. (The methods of altering the thickness of the foregoing sections, are illustrated in plate No. 28.) The cross-hatched sections represent the least areas, and the blank section the added thickness. Tee sections cannot be altered from the standard as given in the tables. Flat bars can be rolled to any thickness between the limits given in the list. 2 WBOUGHT IKON AND STEEL. SIZES OF MINIMUM AND MAXIMUM SECTIONS. PENCOYD BEAMS. , 1. f. 1/0 ^ 1 1 a B q 1 o> fl ^ j ^| Erfs o ii u 3 c g ^ S >> 5 ^ S " P ' i S^ X| ^ fc 1 .5 Jl, '5 -4 !! ll F II M | EH 0) 6 55 * i *, S si S ^ A B B c C D E i 2 15 15 200 145 233 201 i y 5| 54 i ijL f 312 412 168 120 194 1(33 1! A 5 t, 511 i li M 5 101 134 161 M it 5 L 5 li- fi f Kt 108 89 135 109 8 If 3 Mi lt M S 7 10 112 137 * 1 4-| 4] IT? ^ 8 10 90 106 M 4$ f^ H 9 9 90 122 if f 4 4i| ti ^. 10 9 70 88 1 4H f 11 8 81 li,9 32 4 44 41^. i S 12 8 65 75 Tb<- fb- 4 it t f 13 7 65 88 Vs | 8|S 4| i if 14 7 51 88 1 | 4i 1 I 15 6 50 63 it 1 3;T2 3f ii ft 16 6 40 63 f 3 H fi 17 5 34 40 "Ftf iV 2|i 2H ^ 18 5 30 40 3 T 2 -f ff 21 2H i 4 19 4 28 88 -L i O'i 3 ^ _ti 20 4 18.5 21.5 | i 2 t /2 21 3 23 28.6 .1 iV 2^ 2U 1^6 -L 22 3 17 21.7 , 8 A 24 8 The width of the flange varies directly with the thickness of the web. TABLES OF DIMENSIONS. WEIGHTS OF VARIOUS WEB THICKNESSES. PENCOYD BEAMS. Chart Number. to to 1 Ci or J Depth in inches. - MI* | Minimum Web Thick- ness. Minimum Weight per yard. APPROXIMATE WEIGHT IN POUNDS PER YARD FOR EACH THICKNESS OP WEB IN INCHES. (Calculated upon the basis that one Cubic Foot of Iron weighs 480 Ibs.) 1 A a. A * 5 8 t i 1 2 8 4 200.0 145.0 214.0 192.0 233.0 145.0 154.5 173.0 fl 168.0 120.0 179.0 155.5 194.0 125.5 140.5 5 54 6 1 if if H 134.4 108.3 89.3 137.7 118.1 105.8 150.8 131.2 111.6 99.2 92.6 7 8 9 10 11 12 10 10 4 111.7 90.4 111.7 106.0 124.2 136.7 93.6 99.8 9 9 8 8 c-J-cd- *-|CK.|W 90.7 69.8 81.4 65.3 93.5 82.4 99.1 88.1 110.4 121.6 71.2 76.8 S 83.9 75.3 88.9 98.9 108.9 65.3 70.3 13 14 7 7 6 6 1! 65.8 51.4 52^5 56.9 61 .'2 65.8 65.6 70.2 70.0 78.9 78.7 87.7 87 5 15 16 ii 50.0 40.0 53.0 51.0 55.5 55.0 63.0 63.0 40.0 44.0 47.5 17 18 5 5 t 34.0 30.0 aiis 34.0 34.0 37.0 37.8 40.0 40.9 19 20 4 4 4 28.0 18.5 28 21.5 30.5 33.0 35.5 38.0 21 22 3 3 A 23 17.0 28 19^8 24.8 21.7 26.7 28.6 Beams of any weight between the minimum and maximum per yard, given in the table, can be furnished. weight 4 WKOUGHT IRON AND STEEL. SIZES OF MINIMUM AND MAXIMUM SECTIONS. PENOOYD Q B i, CHANNELS. I I ja 0) . | cs 3 i I 1 j fe'S ^T3 ^ OD E - 1 1 Chart Nun Size in inc Minimum per ya Maximum perya Minimum Thicknf Maximum ThickiK Minimum Width Maximum Width H Flange Thi A B B C C D E 30 15 139.0 204.5 A 1 4 41 1 8 31 12 88 5 160.0 if 1 2f 3U 1 A 32 12 60.0 101.5 jj m i! i U 34 10 60.0 106.0 A | 2Af 3iV T6 A 35 10 49.0 86.5 5 1 2^ 2 4 i 2 36 9 53.0 92.0 j^. a i 2-V 2 7 ? a _1| 37 9 37.0 61.0 it i 2fi- 4 - 241 Ii 64 38 39 8 8 43.0 30.0 80.5 r>4.0 A If . | 85 2 n .4.-1 11 H 40 41 7 7 41. 26.0 73.0 49.0 S | 1 2A 1 i 42 6 31.9 54.4 1 fi 2| 2$ A A 43 6 27.6 50.1 -L 5 2 2? ii 1 44 6 22.7 39.6 Ji | If 2:,V ft 45 5 27.3 46.0 ^ | 2 2S it 46 5 18.8 32.9 A i 15. Iff 1 tV 47 4 21.5 31.5 i -1- 1H lit U i 48 4 17.5 23.7 A | i* T 49 3 15.2 18.9 A H 1H Ifi H 'i 50 11.3 11.3 j 4 i H If i i 51 2 8.75 10.0 A 3^ 1A 1A A A 52 If 3.5 3.5 A A if U i A The width of the flange varies directly with the thickness oJ the web. TABLES OF DIMENSIONS. 5 WEIGHTS OF VARIOUS WEB THICKNESSES. FENCOYD \ /CHANNELS. I Chart Number. c 1 Depth in inches. -j 1 Minimum Web Thickness. Minimum Weight per yard. APPROXIMATE WEIGHT IN POUNDS PER YARD FOR EACH THICKNESS OF WEB IN INCHES. Calculated upon the basis that one Cubic Foot of Iron weighs 480 Ibs. i & I & i 5. I 1 1 1 139.0 - 148.0 167.0 186.0 204.5 31 32 34 35 12 12 10 10 if & ~#~ 88.5 60.0 92.0 79.0 100.0 86.5 115.0 101.5 130.0 145.0 160.0 49!6 64.0 63.0 55.0 71.5 60.0 49.0 69.0 61.5 75.5 67.0 81.0 74.0 94.0 86.5 106.0 92^0 30 37 9 9 8 8 7 7 fk if 53 . 37.0 .... 53.0 44.0 45.5 39.0 58.5 1 64.0 49.555.0 70.0 61.0 81.0 38 31) 40 41 A Jl 43.0 30.0 3i!6 50.5 44.0 55.5 49.0 51.0 44 5 60.5 54.0 55.0 49.0 70.5 80.5 64.0 73.0 ig s 41.0 26.0 3i!s 42.0 36.0 46.5 40.0 39.4 35.1 32.1 33.5 2G.6 26.5 23.7 42 43 44 45 46 47 48 49 50 I 6 5 5 4 4 3 2i A I 1 A ~& i 31.9 27.6 22.7 27.3 18.8 21.5 17.5 15.2 11.3 31.9 27.6! 3 27.3 20.4 21.5 18.7 16.1 11.3 35.6 31.41 28.3, 30.4 23.5 24.0 21.2 18.0 43.1 38.9 35.8 3S.7 29.7 29.0 46.9 42.6 39.6 54.4 50.1 39.8 32.9 46.0 31.5 51 52 2 If A 8.75 9.4 ~ A 3.5 Channels of any weight between weight per yard, given in the table, the minimum and maximum can be furnished. 6 WROUGHT IRON AND STEEL. SIZES OF MINIMUM AND MAXIMUM SECTIONS. PENCOYD B Pi?DECK BEAMS. Chart Number. , Size in inches. 'Ec ti 11 c s Maximum Weight per yard. Minimum Web Thickness. Maximum Web Thickness. Minimum Flange Width. Maximum Flange Width. Minimum Bulb Width. Maximum Bulb Width. Bulb Depth. Flange Thickness. Flange Thickness.] A B B C C F F G D E (>(> 12 104.0 138.0 H tt 51 6& OJ. ''B 2^i If M if Gl 11 91.0 118.0 1 | 5i 51 2 2i H a 4 ft 62 10 80.0 105.0 3 1 &i &i ii 2i HI H ii 6;] 9 72.0 94.0 3. B H 5 5i m 2A- Hi 1 f 04 8 61.0 84.0 ft 1 4 4ff m m 1A tt H 65 7 52.0 72.0 H | 41 4M ii iii 1A 1% tV GO 6 42.0 57.0 A A 81 4 1A 1U 1^ H A 67 5 34.0 46.0 rv A H 8| iA l-i 2 ,; -it i I TABLES OF DIMENSIONS. 7 WEIGHTS OF VARIOUS WEB THICKNESSES. PENCOYD o DECK BEAMS. Depth in inches. | Minimum Web Thick- ness. Minimum Weight per yard. APPROXIMATE WEIGHT IN POUNDS PER YARD FOR EACH THICKNESS OP WEB IN INCHES. Calculated upon the basis that one Cubic Foot of Iron weighs 480 Ibs. i A a 8 A i A 1 ti 12 i i .j -i a 104.0 108.0 115.0 123.0 130.0 138.0 11 91.0 91.0 98.0 105.0 111.0 118.0 10 a. 80.0 80.0 86.0 92.0 99 105.0 9 n 8 72.0 .... .... 72.0 77.0 83.0 89.0 94.0 8 7 & 61.0 64 69.0 74.0 79.0 84.0 H 52.0 54.0 58.0 63.0 67.0 72.0 42.0 6 5 A A 42.0 .... 46.0 49.0 53.0 57.0 84.0 .... 34.0 37.0 40.0 43.0 46.0 WROUGHT IRON AND STEEL. PENCOYD ANGLES. EVEN LEGS. WEIGHTS PER YARD OF VARIOUS THICKNESSES. One cubic foot weighing 480 Ibs. Chart Number. SIZE IN INCHES. 1" -.V i" iV' 1" 71.1 U" t" ir I" 1" 120 6 x6 50.6 57.5 64.3 77.8 84.4 69.4 90.6 97.3 110.0 121 5 x5 41.8 47.5 37.5 53.1 41.8 58.6 46.1 (54.0 50.3 74.7 79.8 90.0 122 4 x4 28.6 33.1 54.4 123 3x3 24.8 i" 8 28.7 -a," 32.5 J." 4 36.2 A-" 3D. 8 1" iV' T iV' 5." 124 3 x3 14.4 17.8 21.1 24.3 22.1 27.5 30.6 33.6 125 2Jx23 13.1 16.2 19.2 25.0 126 2j x 2i 11.9 14.6 13.1 17.3 15.5 19.9 17.8 22.5 127 01 v Ol w 4 X ~ 4 10.6 128 2 x2 7.1 9.4 11.513.6.... ... . 129 11*11 6.2 8.1 9.9 11.7 130 HxU 5.3 4.3 6.9 5.6 8.4 9.8 131 lixii 3.0 132 1 xl 2.3 3.4 4.4 TABLE OF DIMENSIONS. PENCOYD ANGLES. UNEVEN LEGS. WEIGHTS PER YARD OF VARIOUS THICKNESSES. One cubic foot weighing 480 Ibs. Chart Number. SIZE IN INCHES i A 3. a * 41. 37.4 35.1 33.0 \ 47.5 42.5 40.0 ^ 53.0 47.4 44.6 f 1 I 79.8 71.1 1 90.0 80.0 140 6 x4 .... 58.6 52.3 49.2 46.0 69.4 61.8 141 5 x4 .... 32.3 30.5 142 5 xS^ 58.1 143 5 x3 .... 28.6 37.5 41.7 54.4 .... 144 4x3 .... .... 26.730.935.0 S9.0 43.0 .... 145 4 x3 26.7 CO 935.0 S9.0J43.0 146 4 x3 .... 21.024.8^8.732.536.239.8 _ 147 3^x3 .... 23.026.5 30.033.4 36.7 148 3 x2i 11.9 16.219.222.125.0 14.617.319.9 I 22.5 149 3 x2 150 3x2 17.8 21.1 34.5 24 3 27.5 85.0 151 6 x3 ... 39.645.0 ! 50.3 55.5165.6 | 5.5 152 153 6|x4 ~ 32.3 44.0 37.4 50.055.9 61.7 73.1 84.295.0 Si x 3.} 42.5 47.4 52.3 61.7 73.1 84.2 95.0 154 7 x3 155 2^x2 10.6 13.1 15.4 17.7 20.0 156 aixu 8.7 10.7 12.6 157 2 xl-i 7.5 9.2 10.8 10 WROUGHT IRON AND STEEL. PENCOYD ANGLES. SQUARE BOOT. WEIGHTS PER YARD OF VARIOUS THICKNESSES. One cubic foot weighing 480 Ibs. CHART NUMBER. 160 SIZE IN INCHES. i A i ft ft i A I 4x4 28.6 33.0 37.6 41.8 46.0 161 3^x3^ 20.8 24.8 28.7 32.5 14'. 4 162 3x3 17.8 21.2 >4.4 27.5 163 164 2fx2f 2^x2i 13.1 11.9 16.2 14.6 19.2 i7! 22.1 19.9 25.0 .... .... 165 166 3i x 2* 10.6 13.1 11.5 15.5 17.8 2x2 ..... ... 9.4 13.6 .... .... 167 If- a If 8.1 6.9 9.9 8.4 11.7 168 li x H .... 5.3 169 U x H .... 4.3 5.6 7.0 .... .... .... ....u... 170 1x1 2.3 3.4 4.4 171 U x {f 5 9 TABLES OF DIMENSIONS. ; ^ 11 PENCOYD TEES. EVEN LEGS. Chart Number. Width of base. g 5 X '1 -jJg- ( 44- x 4" 2 ft IrV x tt " iVfr * 5 x ? 3t It x "1 " 11 ( 6 X i ' 3 t l^f X " I'll? ' 7 X 3 < !" X i " IfV < 8 X 1 < 2^ f If X JL |i < 9 X i. < 2 1 lit X 1 " l| < 10 X JL ' 21 t 2 If X X X i " ll , i it 11 12 X X 1 ' l\ ~ SQUARES. t", -iV, f", H", t", it", i", if", i", w, n", w, H", 1|", 1|", ir', If", U", 2", 24", 2t", 2|", 3", 3-1", 3V, 3|", 4" and 44". ROUNDS. M", 14", i". If", iV, ti", I!", IS", f", H", tt", H", H", f", Jl", IS". M", i", M", F', H", tt", II". Si", II", i", W, W, life", lt",'iA", W, 1^", 14", itr, i^", U", i-.v, it", w, if, if", ij", 2", 2F, 21", 2|", 2t", at", 21", 21-", 3", 8t", 31", 8f", 3f' f 3f", 8f", 3|", 4", 44", 41", 4f ", 44", 4f', 4|", 4J", 5", 51", 64", 5|", 6", 6^" and 7". HALF ROUNDS. i", 1", 11", It", 1|" , 2", 21", 2^, 2f", 3", 34" and 34". MISCELLANEOUS SHAPES. 15 Two grades of iron are manufactured, known respectively as " Pencoyd Refined " and " Pencoyd High Test," the former for all ordinary requirements, the latter for tension members of structures and all purposes where a uniform iron of high duc- tility is required. 10 X AREA IN INCHES = WEIGHT PER YARD IN LBS. In any rolled section of wrought iron, the weight in Ibs. per yard, is precisely equal to ten times its sectional area in square inches. Consequently, either value being known, the other can be in- stantly obtained. AXLES. M^ U$ TT* U- ' // -W*- J MASTER CAR BUILDERS' STANDARD-AXLE Hammered or rolled axles of iron or steel, centred and straightened with journals forged or rough-turned, made to con- form to specifications and tests. STRUCTURAL WORK. The fitting, punching, and riveting of structural work exe- cuted, and iron castings furnished to order. 15 WROUGHT IRON AND STEEL. MISCELLANEOUS SHAPES. CAR BUILDERS' CHANNEL. Chart No. 33. Weight per yard = 50 to 55 Ibs. TEN-INCH BULB PLATE. Chart No. 68. Weight per yard = 62 Ibs. MINERS' TRACK RAIL. Chart No. 190. Weight per yard = 25 Ibs. SPLICE BAR FOR MINERS' TRACK RAIL. Chart No. 191. Weight per yard = 5.2 Ibs. SLOT RAIL FOR CABLE ROAD. Chart No. 192. Weight per yard = 26 Ibs. HALF OVALS. Chart No. 193 = 4.3 Ibs. per yd. Chart No. 194 = 4.8 Ibs. per yd. Channel Rail. Chart No. 195 = 3.5 Ibs. per yard. GROOVED BARS. Chart No. 196 = 8.4 to 14.7 Ibs. per yard. 197 = 1 3 5 to 21 . Ibs. per yard. " 198 = 20 . 9 to 34 5 Ibs. per yard. STRENGTH OF WROUGHT IRON. STRENGTH OF WROUGHT IRON. 17 The tensile strength of rolled iron varies according to the quality of the material, the mode of manufacture, and the sectional area of the bar. In general terms the ordinary sizes of bars of good material may be accepted as having an ultimate tensile strength of 50,000 Ibs. per square inch of section, an elastic limit of 30,000 Ibs., and will stretch 20 per cent, in a length of 8 inches when tested up to rupture. It is, however, as easy to produce the smaller sizes yielding results 10 per cent, higher than the above, as it is difficult to make the largest sections with a limit 10 per cent, below the same figures. Dividing rolled iron into three classes according to its sectional area, we have: I. Bars not exceeding 1$ square inches area. II. Bars from H to 4 square inches area. III. Bars from 4 to 8 square inches area. For which experiments give the following figures as average results. TENSILE STRENGTH ELASTIC LIMIT ELONGATION IN CLASS. PER SQ. INCH. PEU SQ. INCH. 8 INCHES. I. 53,000 Ibs. 33,000 Ibs. 25 per cent. II. 50,000 " 30,000 " 20 " III. 48,000 " 28,000 " 18 " " These, however, are only general conclusions, as much depends on the shape of the section, the method of rolling, and the reduction of area from the pile to the finished bar. The following tensile tests are actual averages taken from our records, and were made on specimens cut from bars of the sizes and shapes given, and intended for use in bridges, and to con- form to the specifications of the leading railroad companies. 2 18 WROUGHT IRON AND STEEL. SIZE AND SHAPE OF BAR. Ultimate strength in Ibs. Per Square Inch. S| ik iifl S OB s^ Per Cent, of Elongation in 8 inches. Per Cent, of Reduction of Fractured Area. One-inch rounds. Two-inch rounds. Four-inch rounds. Four-inch flats. Eight-inch flats. Twelve-inch flats. Three-inch angles. Six-inch angles. Flanges of beams Webs of beams. 52,210 50,935 48,220 51,000 49,500 49,(J80 49,000 49,160 51,840 50,130, 32,150 31,800 26,640 30,000 31,500 31,560 30,500 30,150 31,560 30,150 26 19.8 18 20.7 16 15.5 17 18.1 20.1 17.7 39 31 '30* f to H in- thick. % inches thick. | inches thick. COMPRESSION. The power of wrought iron to resist compression is usually taken as equal to its tensile strength. In the form of flanges for solid beams, this property is exerted to its full capacity, as the adjacent portion of the material in tension sustains the portions in compression from buckling, even when the length of the beam becomes very considerable. But in the form of struts and columns, when the piece becomes of considerable length in pro- portion to its cross-section, failure occurs by bending, or com- bined bending and crushing. (See article on Struts.) Judging from many experiments we have made on bars secured from bending under compressive stress, the elastic limit in compres- sion is a little lower than in tension, but the former not so clearly defined as the latter ; practically they may be considered as equal. These results were derived from small sections; in large sections there may be more equality, as some experiments hereafter de- scribed would denote. With pressures varying from 25,000 to 35,000 Ibs. per square inch, the elastic limit is attained. With 50,000 Ibs. per square inch a permanent reduction of 2^ per cent, of the length is pro- duced; with 75,000 Ibs. a reduction of 6 per cent, and with ELASTICITY OF ROLLED IRON. 19 100,000 Ibs. per square inch the permanent reduction of length is about 8 per cent. These results have a wide range of varia- tion, bufe the figures are the averages of several experiments. ELASTICITY OF ROLLED IRON. The elasticity of wrought iron, or its ratio of change of length under stress below the elastic limit, varies more extensively than any other property of rolled iron. Experiment shows a varia- tion of over 100 per cent, in extreme cases. The modulus of elasticity is an imaginary load, which, suppos- ing the material to be perfectly elastic, would cause the iron to double its length under tension, or to shorten its length one-half under compression, and return to its original length when re- leased from stress. This modulus is usually assumed at 29,- 000,000 Ibs. In large sections of properly prepared material the tensile elasticity probably averages a little over this, and the compressive elasticity a little below it. The following results of the tests for comparative elasticity in tension and compression, will serve to illustrate the irregularity of the elasticity ; also, see tests of iron and steel cut from beams, given hereafter. 20 WROUGHT IRON AND STEEL. Two pieces of 3-inch square iron cut from same bar. Measured length of each specimen = 12 inches. Area of each specimen = .556 square inch. Pressures in Ibs. ; change of length in inches. TENSILE TEST. COMPRESSIVE TEST. Elongations. Bednction of length. Pressure per sq. inch. Load on. Load off. Pressure per sq. inch. Load on. Load off. 5,000 .002 .000 5,000 .002 .000 10,000 .0045 .000 10,000 .0035 .000 15,000 .0065 .000 15,000 .005 .000 20,000 .0085 .000 20,000 .006 .000 22,000 .010 .000 22,000 .007 .000 24,000 .0105 .000 24,000 .008 .000 26,000 .0115 .000 26,000 .009 .000 28,000 .012 .000 28,000 .0095 .000 30,000 .013 .000 30,000 .010 .000 32,000 .0135 .000 32,000 .011 .000 34,000 .0145 .000 34,000 .020 .0035 36,000 .0155 .001 36,000 .023 .0045 38,000 .1715 .1495 38,000 .027 .010 40,000 .3835 .3605 40,000 .107 .089 50,000 1.326 1.2945 50,000 .272 .246 53,820 3.093 60,000 .464 .435 70,000 .'671 ]639 Specimen broke with 53,820 80,000 .845 814 Ibs. per square inch. 90,000 1.074 1.042 Stretched 3.093 in 12 in. 2. 187 in 8 in. Modulus of elasticity " 27. 3 per cent, in 8 in. = 35,300,000 Ibs. Fractured area = .3364 Modulus of elasticity = 27,420,000 Ibs. ELASTICITY OF EOLLED IRON. 21 Two pieces of ^-inch round iron cut from same bar. Measured length of each specimen = 12 inches. Area of each specimen = .449 square inch. Pressure in Ibs. ; change of length in inches. TENSILE TEST. COMPRESSION TEST. Elongations. Reduction of length. Pressure per Load on. Load off. Pressure per Load on. Load off. sq. inch. sq. inch. 5,000 .002 .000 5,000 .002 .000 10,000 .004 .000 10,000 .005 .000 15,000 .OC6 .000 15,000. .007 .000 20,000 .008 .000 20,000 .010 .000 2,1,000 .009 .000 2-J.OOO .011 .001 24,003 .010 .000 24,000 .012 .002 26,000 .0105 .000 26,000 .013 .003 28,000 .011 .000 28,000 .015 .0045 30,000 .013 .000 30,000 .o-as .0065 32,000 .014 .('00 32,000 .02-^5 .007 34,000 .015 .002 34.000 .0275 .009 30,000 .022 .007 36,000 .040 .019 38,000 .416 .399 38,000 .052 .036 40,000 .544 .52 3 40,000 .133 .114 50,000 1.740 1.707 50,000 .304 .283 51,600 2.468 60,000 .427 .402 70,000 .546 .521 Specimen broke with 51,600 80,000 .663 .635 Ibs. per square inch. 90,000 .773 .742 Stretched 2. 468 in 12 in. 100,000 .896 .862 1.81 in 8 in. " 22. 6 per cent, in 8 in. Modulus of elasticity Fractured area = .297 sq. in. Modulus of elasticity = 29,400,000 Ibs. =24,490,000 Ibs. 22 WROUGHT IRON AND STEEL. A series of tests was made on the United States Government testing machine at Watertown Arsenal, on the full-sized bars, of which the following is a condensed average. TENSILE TESTS. K d" c . gh a |* "" o ft MODE OF MANU- JS Zo, -^ * gf tSjf o c VjD o 85 . ll FACTURE. g"" 1 ~ ^ " C a p '- S.S 5 ^5.97j 21.62 ?4 20.91 19.29 16.83 14.15 .30 W 16 28.93 26.53 21.35 20. -27 27 19.60 18.08 15.76 13.26 .34 g 17 27.23 24.96 22.92 19.08 .30 18.45 17.02 14.85 12.48 .38 ^ 18 25.72 23.58 21.64 18.02 34 17.42 16.07 14.02 11.79 .43 K 19 24.36 22.34 20.51 17.07 38 16.51 15.23 13.28 11.17 .48 20 23.14 21.22 19.48 16.21 42 15.68 14.47 12.62 10.61 .53 21 22.04 20.21 18.55 15.44 .46 14.93 13.78 12.02 10.11 .58 OQ 22 21.04 19.29 17.71 14.74 .51 14.25 13.15 11.47 9.65 4 23 20.13 18.45 16.94 14.10 .56 13.63 12.58 10.97 9.23 .70 &H 24 19.29 17.68 16.23 13.51 .61 13.07 12.05 10.52 8.84 .77 25 18.52 16.98 15.58 12.97 .66 12.54 11.57 10.10 _8J9L83 g 36 g 27 17.80 17.14 16.32 15.72 14.99 14.43 12.47 12.01 .72 77 12.06 11.61 11.13 10.72 9.71 9.35 8.16 .90 7.86 .97 H 28 16.53 15.16 13.91 11.58 83 11.20 10.33 9.01 7.581.05 S 29 15.96 14.63 13.43 11.18 .89 10.81 9.98 8.70 7.32 1.12 30 15.43 14.15 12.99 10.81 95 10.45 9.64 8.41 7.07 1.20 31 14.93 13.69 12 57i 10.46 1 0?, 10.12 9.33 8.14 6.85 1.28 32 14.47 13^6 ira 10.13 l"09 9.80 9.04 7.89 6.63 1.36 33 14.03 12.86 11.81 9.83 1.16 9.50 8.76J 7.65 6.43 1.44 TABLE OF SAFE LOADS. 41 PENCOYD 101" BEAMS. 10" Maximum and Minimum sections of each shape. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for each size of beam. For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be y - of the tabular deflection. CHART NUMBER. 5 5 E* 5t 6 6 GC 7 7 8 8 H 1 SIZE OF BEAM IN iot" iot" ict" ict" iot" ict" < 10" 10" 10" 10" INCHES. 1-1 o WT. PER M YARD IN 161 134 135 108 109 89 137 112 106 90 LBS. fc 92 MOMENT 1 ! fc OF 265.7 241.6 219.5 195.4 180.3 162.3 194.4 173.6 161.3 148.3 INERTIA. H H GREATEST SAFE LOAD. W fi GREATEST SAFE LOAD 1 10 23.62 21.49 19.51 17.37 16.03 13.35 .15 18.14 16.20 15.08 13.84 .16 11 21.47 19.54 17.74 15.79 14.57 13.11 .18 16.49 14.73 13.71 12.58 .19 12 19.68 17.91 16.26 14.48 13.3H 12.02 .22 16.13118.50 12.57 11.54 .23 13 18.17 16.53 15.01 13.36 12.33 11 09 23 13 95 12 46 11.60 10.65 .27 14 16.87 15.35 13.94 12.41 11.4-) 10.30 .30 12.94 11.57 10.77 9.89 .3] 15 15.75 14.33 13.01 11.58 10.69 9.61 .34 12.0910.80 JO. 05 9.23 .36 H 16 14.76 13.43 12.19 10.86 10.02 9.01 .39 11.34 10.13 9.42 8.65 .41 13.90 12.64 11.48 10.22 9.43 8.48 .44 10.67 9.53 8. 87 8.14 .46 ^ 18 13.12 11.94 10.84 9.65 8.91 8.01 .49 10.08 9.00 8.38 7.fi9 .52 19 12.43 11.31 10.27 9.14 8.44 7.59 .55 9.55! 8.53 7.94 7.29 .58 H 20 11 81 10.74 9.75 8.69 8.01 7.21 .61 9.071 8.10 7.E4 6.92 .64 21 J1.25 10.23 9.29 8.27 7.63 6.87 .6*! Tel T72 TTs T^"S On MataMi mean** t ^ 1 """" " M 22 10.74 9.77 8.87 7.90 7.28 6.55 .74 8.25 7.36 6.85 6.29 .78 & 23 10.27 9.34 8.48 7.55 6.97 6.27 .81 7.89 7.04! 6.56 6.02 .85 24 9.84 8.95 8.13 7.24 6. 68 6.01 .83 7.56 6.75! 6.28 5.77 .92 K 25 9.45 8.60 7.80 6.95 6.41 5.77 .95 7.26 6.48 6.03 5.54 1.00 H < 26 9 00 8 27 7 51 6 6*3 fi 16 5 54 1 03 6 98 6 23 5 80 5 32 1 08 8.75 7.96 7.23 6.43 5.94 5.34 1.11 6.72 6.00! 5.59 5.13 1.17 3 28 8.43 7.67 6.97 6.20 5.72 5.15 1.19 tf.48 5.79 5.39 4.94 1.26 29 8.14 7.41 6.73 5.99 5.53 4.97 1.28 6.26 5. 59 5.20 4.77 1.35 30 7.87 7.17 6.51 5.79 5.34 4.80 1.37 6.05 5.40 5.03 4.61 1.44 31 7 6" 6 93 6 29 5 60 5 16 4.65 1 46 5 85 5 23 4 86 1 4 47 1 54 32 7.38 6.72 6.09 5.43 5.01 4.50 1.57 5.67 5.061 4.71 4.33 1.64 33 7.19 6.51 5.91 5.26 4.86 4.37 1.68 5.50 4.91 4.57 4.19 1.75 WROUGHT IRON AND STEEL. 9" PENCOYD 8" BEAMS. Maximum and Minimum sections of each shape. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflection in incites corresponding to given loads for each size of beam. For load in middle allow one-half the tabular figures. Deflection for latter load will be -jjo of the tabular deflection. CHART NUMBER. 9 9 10 10 W 11 11 12 12 * M < SIZE OF BEAM IN INCHES. 9" 9" 9" 9" B 8" 8" 8" 8" S> WT. PER YD. IN LBS. 122 90 QQ 70 C- g 00 109 81 75 65 1 MOMENT OF INERTIA. 143.7 118.8 106.8 94.4 o 98.6 3.9 74.5 09.2 1 GREATEST SAFE LOAD. c p GREATEST SAFE LOAP. 1 6 24.27 16.53 18.42 9.94 .06 19.22 15.49 14.48 10.46 .07 7 20.80 16.53 15.79 9.94 .08 16.47; 13.99 12.41 10.46 .10 8 18.20 15.40 13.81 9.94 .11 14.41 12.24 10.86 10.08 .13 9 10.18 13.69 12.27 9.94 .14 12.81 10.88 9.66 8.96 .16 10 14.56 12.32 11.05 9.79 .18 11.53 9.79 8.69 8.07 .20 EH 11 13.24 11.20 10.04 8.90 .22 10.48 8.90 7.90 7.33 .24 W 12 12.13 10.26 9.21 8.16 .26 9.61 8.16 7.24 6.72 .29 g 13 11.20 9.48 8.50 7.53 .30 8.8? 7.53 6.68 6.21 .34 *r 14 10.40 8.80 7.89 7.00 .35 8.24 6.99 6.21 5.76 .39 G 15 9.71 8.21 7.37 6.53 .40 7.69 6.53 5.79 5.38 .45 16 9.10 7.70 6.91 6.12 .46 7.21 6.12 5.43 5.04 .51 5j 17 8.56 7.25 6.50 5.76 .52 "T78 T76 -5J2 T74 "58 PH 03 18 8.09 6.84 6.14 5.44 .58 6.41 5.44 4.83 4.48 .65 fa 19 7J86 "O8 ""f)"s2 Tl5 -64 6.07 5.15 4.57 4.24 .72 20 7.28 e!i6i s!52 4.90 .71 5.76 4.89 4.34 4.03 .80 21 6.93 5.86 5.25 4.66 .78 5.49 4.66 4.14 3.84 .88 H 22 6.62 5.60 5.02 4.45 .86 5.24 4.45 3.95 3.07 .97 23 6.33 5.8o| 4.80 4.25 .94 5.01 4.25 3.78 3.50 1.06 W 24 6.07 5.13! 4.61 4.08 1.02 4.80 4.08 3.62 3.36 1.16 K; 25 5.82 4.93 4.42 3.92 1.11 4.61 3.91 3.48 3.22 1.26 26 5.60 4.74 4.25 3.77 1.21 4.43 3.77 3.34 3.10 1.36 27 5.39 4.561 4.09 3.631.30 4.27 3.62 3.22 2.98 1.46 28 5.20 4.40 3.95 3.50 1.40 4.12 3.50 3.10 2.88 1.57 29 5.02 4.25 3.81 3.381.50 3.98 3.37 3.00 2.78 1.68 TABLE OF SAFE LOADS. 7" PENCOYD 6" BEAMS. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for eacli size of beam. For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be ^o of the tabular deflection. CHART NUMBER. 13 13 14 14 05 1 15 15 16 16 5 SIZE OF BEAM IN INCHES. 7" 7" 7" 7" M i- 6" 6" 6" 6" H WT. PER YD. IN LBS. 88 75 63 51 i to 63 55 48 40 1 (0 MOMENT OF INERTIA. 58.6 53.3 48.0 43.1 O 30.8 27.5 26.3 24.1 O 1 3 3 E E GREATEST SAFE LOAD. ft GREATEST SAFE LOAD. 1 6 12.93 11.75 10.65 6.17 .08 8.03 7.42 6.87 6.25 .10 7 11.09 10.07 9.13 6.17 .11 6.89 6.36 5.89 5.36 .13 8 9.70 8.81 7.99 6.17 .15 6.02 5.56 5.15 4.C9 .17 9 8.62 7.83 7.10 6.17 .19 5.36 4.94 4.58 4.17 .22 10 7.76 7.05 6.39 5.74 .23 4.82 4.45 4.12 3.74 .27 ^ 11 7.05 6.41 5.81 5.22 .28 4.38 4.05 3.75 3.41 .32 H 12 6.47 5.87 5.32 4.79 .33 4.02 3.71 3.43 3.12 .38 g 13 5.97 5.42 4.92 4.41 .38 T77 nra TIT T^ "43 fc 14 5.54 5.04 4.56 4.10 .44 3.44 3.18 2.94 2.68 .52 15 TTT "4*70 T38 -O "51 3.21 2.97 2.75 2.50 .60 fc 16 4.85 4.41 3.99 3.59 .58 3.01 2.78 2.57 2.34 .69 <5 17 4.5(3 4.15 3.76 3.38 .66 2.84 2.62 2.42 2.21 .78 PH 60 18 4.31 3.92 3.55 3.19 .74 2.68 2.47 2.29 2.08 .87 fc 19 4.08 3.71 3.36 3.0-2 .82 2.54 2.34 2.17 1.97 .97 20 3.88 3.52 3.19 2.87 .90 2.41 2.22 2.06 1.87 1.07 21 3.70 3.36 3.04 2.73 .99 2.30 2.12 1.96 1.78 1.18 M EH 0-2 3.53 3.20 2.90 2.61 1.09 2.19 2.02 1.87 1.70 1.29 S 23 3.37 3.07 2.77 2.491.20 2.10 1.93 1.79 1.63 1.41 g 24 3.23 2.94 2.66 2.39 1.33 2.01 1.85 1.72 1. 5611.54 3 25 3.10 2.82 2 56 2.30 1.43 1.93 1.78 1.65 1.50 1.67 26 2.98 2.71 2.46 2.21 1.55 1.85 1.71 1.58 1.44 1.81 27 2.87 2.61 2.37 2.121.67 1.78 1.65 1.53 1.39,1.95 28 2.77 2.52 2.28 2.051.80 1.72 1.59 1.47 1.34 2.10 29 2.68 2.43 2.20 1.981.93 1.66 1.53 1.42 1.2912.25 44 WROUGHT IRON AND STEEL. 5" PENCOYD BEAMS. 4" Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for each size of beam. For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be & of the tabular deflection. CHART NUMBER. 17 17 18 18 oc 1 19 19 20. 20. ai m SIZE OF BEAM IN INCHES. 5" 5" 5" 5" ~ H is 4" 4" | 4" 4" w Tj< WT. PER YD. IN LBS. 40 36 33 30 M tt 38 28 21.5 18.5 03 ^ MOMENT op INERTIA. 14.7 13.7 13.1 12.5 LECTIO! 9.0 7.7 5.5 5.1 O GREATEST SAFE LOAD. h a P GREATEST SAFE LOAD. W ft 4 6.80 6.42 6.12 4.86 .05 5.25 4.47 3.27 3.00 .06 5 5.44 5.14 4.90 4.67 .08 4.25 3.58 2.6-2 2.40. .10 6 4.53 4.28 4.08 3.89 .12 3.50 2.98 2.18 2.00 .14 7 3.89 3 67 3.50 3.33 .16 3.00 2.56 1.86 1.71 .20 8 3.40 3.21 3.06 2.92 .21 2.62 2.24 1.64 1.50 .28 FH 9 3.02 2.86 2.72 2.59 .26 ~33 i.yy 1.46 TB -33 H 10 2.72 2.57 2.45 2.33 .32 2.10 1.79 1.31 1.20 .40 11 7 TM "T23 "TT2 "39 1.91 1.63 1.19 1.09 .49 K 12 2.27 2.14 2.04 1.94 .46 1.75 1.49 1.09 1.00 .58 M 13 2.09 .98 .88 1.79 .54 1.62 1.88 1.01 .92 .68 fc H 1.94 .84 .75 1.67 .63 1.50 1.28 .94 86 .79 3 15 1.81 .71 .63 1.55 .72 1.40 1.19 .87 80 .91 OH 50 16 .70 .61 .53 1.46 .82 1.31 1.12 .82 .75 1.03 EC, 17 .60 .51 .44 1.37 .93 1.23 1.05 .77 .71 1.17 18 .51 .43 .36 1.30 1.04 1.17 .1)9 .73 .671.31 19 .43 .35 .29 1.23 1.16 1.11 .94 .69 .631.48 PS 20 .36 .28 .22 1.17 1.29 1.05 .89 .65 .60 1.61 25 21 .29 .22 .17 1.11 1.42 1.00 .85 ,6'2 .571.77 23 .24 .17 .11 l.Olil.58 .95 .81 .60 .541.93 3 23 .18 .12 .07 1.01 1.70 .91 .78 .57 .522.12 24 .13 1.07 1.02 .97 1.85 .87 .75 .55 .50,2.32 25 .09 1.03 .98 .93 2.01 .84 .7-2 .52 .48^2.51 26 .04 .99 .94 .902.18! .81 .69 .50 .46 2.71 27 1.01 .95 .91 .86 2.36 .78 .66 .48 .44 2.91 TABLE OF SAFE LOADS. 45 PENCOYD BEAMS. Maximum and Minimum sections of each shape. Greatest safe load in Net Tons evenly distributed including beam itself. Deflections in inches corresponding to given loads for each size of beam. For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be 'nT of the tabular deflection. CHART NUMBER. 21 21 22 22 a SIZE OP BEAM IN INCHES. 3" 3" 3" 3" | WT. PER YD. IN LBS. 28.6 23 21.7 17 2 OB MOMENT op INERTIA. 4.0 3.3 3.0 2.7 I GREATEST SAFE LOAD. 1 4 2.87 2.56 2.34 2.07 .09 5 2.30 2.05 1.87 1.88 .14 6 1.92 1.71 1.56 1.38 .19 7 -1-64 HT1& "T34 -n "26 &3 8 1.44 1.28 1.17 1.03 .34 fe 9 1.28 1.14 1.04 .92 .43 ^ 10 1.15 1.02 .94 .82 .53 S 11 1.04 .93 .85 .75 .65 fc 12 .96 .85 .78 .69 .77 ^ 13 3 14 15 .88 .82 .77 .79 .73 .68 .72 .67 .62 .64 .59 .55 .91 1.05 1.21 C 16 17 g 18 | .64 .60 .57 .58 .55 .52 .521.37 .491.55 .4611.74 g 19 .61 .54 .49 .44 1.93 W 20 .58 .51 .47 .41 2.13 ^ 21 .55 .49 .45 .39 2.37 22 .52 .47 .43 .38 2.62 23 .50 .44 .41 .36 2.88 46 WROUGHT IKON AND STEEL. PENCOYD 15" CHANNELS. 12" Maximum and Minimum sections of each shape. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for each size of channel. For a load in middle of beam, allow one-half the tabular figures. Deflection for latter load will be -fa of the tabular deflection. CHART NUMBER. 30 30 $ w 31 31 32 32 w SIZE OF CHAN- NEL IN INS. 15" 15" fc BE 12" 12" 12" 12" 3 WT. PER YD. IN LBS. 204.5 148 K 160 88.5 101.5 60 1 8 g MOMENT OF INERTIA. 557.4 451.5 CO 'EH g 268.5 182.7 173.5 123.7 03 GREATEST SAFE LOAD. 1 GREATEST SAFE LOAD. d 1 10 34.68 28.09 .11 20.88 14.21 13. 4C 9.14 .13 11 31.53 25.54 .13 18.98 12.!I2! 12.26 8.75 .16 12 28.90 23.41 .15 17.40 11.84 : 11.24 8.02 .19 13 26. 63 21.61 .18 16.06 10.93 10.38 7.40 .22 14 24.77 20.08 .21 14.91 10.15 9.64 6.87 .26 EH 15 23.12 18.73 .24 13.1(2 9.47i 8.99 6.41 .30 W 16 21.68 17.56 .27 13.05 8.88 8.43 6.01 .34 g 17 20.40 16.52 .30 12.28 8.36 7.94 5.66 .38 !z 18 19.27 15.61 .34 11.60 7.89 ' 7.49 5.34 .43 B 19 18.25 It. 78 .38 10.99 7.48 7.10 5.06 .48 20 17.34 14.04 .43 10.44 7.10 6.74 4.81 .53 5 21 16.52 13.38 .47 9.94 6.77 6.42 4.58 .58 OQ 22 15.76 12.77 .52 9.49 6.46 6.13 4.37J .64 23 15.08 12.21 .57 9.08 6.18 5.87 4.18i .70 PM 24 14.45 11.70 .62 8.70 5.92 5.62 4.01 .77 25 13.87 11.24 .67 8.35 _5.(i8 5.40 3.85 .83 g 36 13.34 10.80 .73 8M 5.47 5.19 3.70 .90 O 27 12.85 10.40 78 7.73 5.26 5.00 3.56 .97 28 12.39 10.03 84 7.46 5.07 4.82 3.44 1 05 3 29 11.96 9.69 .90 7.20 4.90 4.65 3!32lll2 30 11.56 9.36 .96 6.96 4.74 4.50 3.21,1.20 31 11.19 9.06 1.03 6.74 4.58 4.35 3.101.28 32 TOl "T78 ^^^ ^"^ iTo 6.52 4.44 4.22 3.0111.36 33 10.51 8.51 1.17 6.33 4.31 4.09 2.921.44 TABLE OF SAFE LOADS. 47 PENCOYD 10" CHANNELS. 9" Maximum and Minimum sections of each shape. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for each size of channel. For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be -j 8 - of the tabular deflection. CHART NUMBER. 34 34 35 35 H & 36 36 37 37 i SlZEOFCHAN- NEL IN INS. 10" 10" 10" 10" -T 16 4.37 2.91 2.99 2.06 .51 3.54 2.46 2.32 1.54 .59 < 17 -os "Tr4 T8I HT4 -58 3.34 2.31 2.18 1.45 .67 * 18 3.89 2.59 2.66 1.83 .65 3.15 2.18 2.06 .37 .75 fr 19 3.68 2.45 2.52 1.73 .72 2.98 2.07 1.95 .29 .83 20 3.50 2.33 2.39 1.64 .80 2.83 1.96 1.85 .23 .92 21 3.33 2.22 2. 8 1.57 .88 2.70 1.87 1.77 .17 1.01 E-| 2 3.18 2.12 2.17 1.50 .97 2.58 1.79 1.69 .121.11 i 2:i 3.04 2.03 2.08 1.43 1.06 2.47 1.71 1.61 .071.22 W 24 2.92 1.94 1.99 1.37 1.16 2.36 1.64 1.55 .021.34 H; 25 2.80 1.86 1.91 1.32 1.26 2.27J 1.57 1.48 .98jl.45 26 2 61 1.79 1.84 1.26 1.36 2.18 1.51 1.43 .95'l.57 27 2.59 1.73 1.77 1.22 1.46 2.10 1.46 1.37 .91J1.69 28 2.50 1.66 1.71 1.17 1.57 2.02 1.40 1.32 .88 1.82 89 2.41 1.61 1.65 1.13 1.68 1.95 1.35 1.28 .851.95 TABLE OF SAFE LOADS. PENCOYD H 5" and 6" jl 3" and 4" CHANNELS. Maximum and Minimum sections of each shape. Greatest safe load in Net Tons evenly distributed including beam itself. Deflections in inches corresponding to given loads for each size of chanm* For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be TJ of the tabular deflection. CHART NUMBER. 3 42 44 45 46 M g 47 48 49 49 1 W SIZE OF ! \ * * CHANNEL IN INS. I 6" 6" 5" 5" 3 5 5 ~WT. PER ^ * cb YD. IN b 33.0 23 27 18.8 o r* 21.5 17.5 18.9 15.2 g LBS. o PH fr MOM. OF INERTIA. 1 18.4 11.7 10.3 6.7 fe fc 5.2 4.1 2.3 2.0 1 3 1 GREATEST SAFE LOAD. K K ft ft GREATEST SAFE LOAD. ft .02 6.50 5.24 5.92 4.13 .02 .03 4.03 3.20 2.40 2.10 .05 4 .04 6.50 4.54 4.80 3.10 .05 .06 3.02, 2.40 1.80 1.57 .09 5 .07 5.70 3.63 3.84 2.48 .08 .10 2.42 1.92 1.44 1.26 .14 FH' 6 .10 4.75 3.02 3.20 2.07 .12 .14 2.02 1.60 1.20 1.05 /L9 &3 7 .13 4.07 2.59 2.74 1.77 .16 .20 1.73 1.37 1.03 .90 .26 ^ 8 .17 3.56 2.26 2.40 1.55 .21 .2* 1.51 1 1.20 .90 .79 .34 Y-r 9 .22 3.17 2.01 2.13 1.38 .26 O)7 .80 .70 .43 K 10 .27 2.85 1.81 1.92 1.24 .32 .40 1.21 .96 .72 .63 .53 % n .32 2.59 1.64 1.74 1.13 .39 .49 1.10 .87 .65 .57 .65 PH 12 .38 2.37 1.51 1.60 1.03 .46 .58 1.01 .80 .60 .52 .77 W 13 "45 2.19 ""7^J9 1.48 .95 .54 .68 .93 .74 .?5 .48 .91 fe 14 .52 2.04 i!s3 1.37 .89 .63 .79 .86 .69 !51 .45 1.05 C 15 .60 1 90 1.21 1.28 .83! .72 .91 .81 .64 .48 .42 1.21 5 16 .69 1.78 1.13 1.20 .77 .82 1.03 .76 .60 .45 .39 1.37 g 17 .78 1.H8 1.06 1.13 .73 .93 1.17 .71 .56 .42 .37 1.55 | 18 .87 1.58 1.01 1.07 .691.04 1.31 .67 .53 .40 .35 1.74 ^ 19 .97 1.50 .95 1.01 .651.16 1.46 .64 .n .38 .33 1.93 20 1.07 1.42 .90 .96 .621.29 1.61 .60 .48 .36 .31 2.13 21 1.18 1.36 .86! .91 .591.421 1.77 .58 .46! .34 .SO 2.37 22 1.29; 1.30 .82 .87 .56 1.56 1.93 .55 .44 .33 .29 2.62 23 1.41 1.24 .79 .83 .541.70 2.12 .53 .42 .31 .27 2.88 24 1.54 1.19 .75 .80 .52 1.85 12.32 50 .40 .30 26 3.11 25 1.67 1.14 .72 .77 .502.01 2.51 .48 .38 .29 .25 3.34 26 1.81 1.101 .70 .74 .482.18 1 2.71 .47 .37 .28 ,24 3.50 WKOUGHT IRON AND STEEL. PENOOYD 12" and 11" BEAMS. 10" and 9" Maximum and minimum sections of each shape. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for each size of beam. For a load-in middle of beam allow one-half the tabular figures. Deflection for latter load will be W of the tabular deflection. CHAUT NUMBER. * 60 60 61 61 fi 1 oo 62 62 63 63 m g SIZE OF H M PQ PQ BEAM IN PQ 12" 12" 11" 11" 10" 10" 9" 9" s INCHES. fe o os WT. PER 'K a a M YD. IN o 138 104 118 91 I I 105 80 94 72 fe LBS. OQ 1 MOM OF. INERTIA. O 264.9 222.0 193.1 164.1 o H 140.4 118.2 99.5 84.8 g w w W 1 w K i i h s GREATEST SAFE LOAD. H ft H ft GREATEST SAFE LOAD. ft 10 .13 20.59 17.26 16.41 13.95 .15 .16 13.11 11.03 10 32 8.79 .18 11 .16 18.72 15.69 14.92 12.68 .18 .19 11.92 10.031 9.38 7.99 .22 12 .19 17.16 14.38 13.67 11.62 .21 .23 10.92 9.19 8.60 7,32 .26 13 .22 1J.84 13.28 12.62 10.73 .25 .27 10.08 8.48 7.94 6.76 .30 14 .26 14.71 12.33 11.72 9.96 .29 .31 9.36 7.88 7.37 6.28 .35 . 15 .30 13.73 11.51 10.94 9.30 .36 8.74 7.35 6.88 5.86 .40 B 17 34 12.87 10.79 10.26 8.72 ^39 .41 8.19 6.89 6.45 5.49 .47 .38 12.11 10.15 9.65 8.21 .44 .46 7.71 6.49 6.07 5.17 .53 s 18 .44 11.44 9.59 9.12 7.75 .49 .52 7.28 6.13 5.73 4.88 .59 5 19 49 10.84 9.08 8.64 7.34 .54 .58 6.90 5.81 4.6.3 "65 20 !54 10.29 8.63 8.20 6.97 .59 .64 6.55 5.51 5!l6 4.39 .72 * 21 .59 9.80 8.22 7.81 6.64 .65 6.24 -ns 4.91 4.19 .79 2 22 .65 9.36 7.8r> 7.46 6.34 .71 .78 5. 90 5.01 4.69 4.00 .87 & s .71 8.95 7.50 -7-15 "77 .86 5.70 4.80 4.49 3.82 .95 o ** .78 8.58 7.19 6.84 s!si .84 .93 5.46 4.60 4.30 3.661.04 25 w "84 "is 6.90 6.56 5.58 .91 1.01 5.24 4.41 4.13 3.52 1.13 .92 7.92 6.64 6.31 5.37 .99 1.09 5.04 4.24 3.97 3.38 1.23 ^ 27 .99 7.63 6.39 6.08 5.17 1 07 1.18 4.86 4.09 3.82 3.261.32 1.07 7.35 6.16 5.88 4.98 1.15 1.27 4.68 3.94 3.69 3.141.42 i-J 29 1.14 7.10 5.95 5.66 4.81 1.23 1.38 4.52 3.80 3.56 3.03 1.52 30 1.22 6.86 5.75 5.47 4.65 1.32 1.45 4.37 3.67 3.44 2.93 1.65 31 1.30 6.64 5.57 5.29 4.50 1.41 1.55 4.23 3.56 3.33 2.84 1.77 32 1.33 6.43 5.39 5.13 4.36 1.50 1 65 4.10 3.45 3 22 2.751.90 33 1.46 6.24 5.23 4.97 4.23 1.60 1.76 II 3.97 3.34 3.13 2.66 2.03 TABLE OF SAFE LOADS. 51 PENCOYD 8" and 7" 6" and 5" O BEAMS. Maximum and minimum sections of each shape. Greatest safe load in Net Tons evenly distributed, including beam itself. Deflections in inches corresponding to given loads for each size of beam. For a load in middle of beam allow one-half the tabular figures. Deflection for latter load will be -*o~ of the tabular deflection. CHART NUMBER. i 64 64 65 65 A i < X < 66 66 67 67 4 SIZE OF BEAM w 8" 8" 7" 7" M w M 6" 6" 5" 5" m M IN IN*. So _ b io WT. PER a ff 6S K YD. IN 84 61 72 52 O o 57 42 46 34 g LBS. * m 3B MOM. OF INERTIA. o 70.5 57.7 42.6 34.4 I ECTION 26.5 22.0 14.5 12.0 55 O ft GREATEST SAFE LOAD. 1 U ft GREATEST SAFE LOAD. M ft 6 .07 19.53 11.22 9.43 7.63 .08 .10 6.87 5.70 4.53 3.73 .12 7 .10 in. 74 9.61 8.09 6.54 .11 .13 5.89 4.89 3.89 3.20 .16 8 .13 14.65 8.41 7.07 5.73 .15 .17 5.15 4.27 3.40 2.80 .21 .16 13.02 7.48 6.29 5.09 .19 .22 4.58 3.02 2.49 .26 &q 10 .20 11.72 6.73 5.66 4.58 .23 27 4.12 3.42 2.72 2.24 .32 fe 11 24 10.65 6.12 5.15 4.16 .28 .32 3.75 3.11 -2-47 "T04 -39 .29 9.77 5.61 4.72 3.82 .33 .38 3.43 2.85 2.27 1.87 .46 B 13 .34 9.01 5.18 4.35 3.52 .38 "45 "Or 2.63 2.09 1.72 .54 5 14 .39 8.37 4.81 4.04 3.27 .45 .52 2.94 2.44 1.94 1.60 .63 eu 15 .45 7.81 4.49 -3T7 "Tos T2 .60 2.75 2.28 1.81 .49 .72 16 .51 7.33 4.21 3.54 2.86 .59 .69 2.57 2.14 1.70 1.40 82 &. 17 "58 6.89 "^96 3.33 2.69 .67 .78 2.42 2.01 1.60 .32 .93 C 18 .65 6.51 3.74 3.14 2.54 .75 .87 2.29 1.90 .51 .24 1.04 g 19 .72 6.17 3.54 2.98 2.41 .83 .97 2.17 1.80 .43 .18 1.16 pO .80 5.86 3.36 2.83 2.29 .92 1.07 2.06 1.71 .36 .12 1.29 .88 5.58 3.20 2.69 2.18 1.01 1.18 1.96 1.63 .30 .07 1.42 Cd ^ 22 .97 5.33 3.06 2.57 2.08 1.11 1.29 1.87 1.55 .24 1.02 1.56 23 1.06 5.10 2.9.3 2.46 .99 1.22 1.41 1.79 1.49 .18 .97 1.70 24 1.16 4.88 2.80 2.36 91 1.34 1.54' 1.72 1.42 .13 .93 1.85 25 1.26 4.69 2.69 2.26 .83 1.45 1.67 1.65 1.37 .09 .90 2.01 26 1 36 4.51 2.59 2.18 .76 1.571 1.81 1.58 1.32 1.05 .86 2.18 27 1.46 4.34 2.49 2.10 .701.69 1.95 1.53! 1.27 1 01 .83 2 36 28 1.57 4.19 2.40 2 02 .641.82 2.10 1.47 1.22 .97 .80 2 54 29 1.68 4.04 2.32 1.95 .58 1.95 2.25 1.42 1.18 .94 2.73 1 52 WROUGHT IRON AND STEEL. IRON FLOOR BEAMS. When I beams are used as floor joists or girders, the spacing and proper size of beams depends on the amount and character of the loads, as well as the distance to be spanned. Not only the positive strength, but the elasticity or amount of deflection per- missible must be considered. A heavy load per unit of area may not require as strong a floor as that necessary for a lighter one, if the latter be liable to sudden application, especially if accompanied with impact, while the normal state of the heavier load is quiescence, or slow and even change. It would require a special treatise to describe the subject, and those lacking experience are referred to the published literature which is now very ample and complete. It has been demonstrated that the greatest mass of men that can be packed on any floor will not exceed in weight 80 Ibs. per square foot. The weight of the iron beams will depend on the span, for which see a general rule farther on. If brick arches are Inid between the beams, the weight of a 4" course of brick, including the concrete filling, will be about 50 Ibs. per square foot. Within the limits of length of span in which rolled I beams can be used, it may be assumed that a floor is safe to sustain the greatest possible load of men, when the following loading does not exhibit a greater bending stress on the beam than that de- noted in the tables, under the head of " Greatest Safe Load Dis- tributed," pages 40-51. I Beam joists with wooden floor 100 Ibs. per square foot. Wooden floor and plastered ceilings =110 " " " " 4" brick arches and concrete filling 150 " " " " These figures represent the total weight of floor itself and the imposed load. When the floor beams are subject to the action of moving loads, it is necessary to make allowance for a greater nominal weight than actually may occur, especially if the span is long in proportion to the depth of the beam. If the beams are too light, the resulting tremor and vibration will be a source of dis- comfort to the user, if not of weakness to the structure. The same results are obtained by assuming either a higher nominal load per unit of area than actually can occur, or adopting a higher factor of safety, than given in our tables, for the actual WEIGHT OF IRON IN FLOOB BEAMS. 53 loads. Floors proportioned as follows for given purposes will be found satisfactory. The weight of the material may be included in the figures. CHARACTER OP FLOOR. LOAD PER SQ. FT. Very lightest floors, plank covering . 100 Ibs Very lightest floors, brick arches 150 " Light warehouse floors 9QO " Halls of audience 200 " Warehouses in which heavy pieces are moved. . Shop floors for light machinery 250 " 250 " Shop floors for heavy machinery. 300 to 500 Ibs GENERAL RULE FOR THE WEIGHT OF IRON IN FLOOR BEAMS. When the standard section of any size of beam is used, the weight of iron obtained by the following rule will be found to approximate closely to the actual amount required: " Square of span in feet divided by 5 times the depth of the beam in inches, equals the pounds of iron in the beams per square foot of floor "f- 8 ^ 2 ,-, = Ibs \5 x depth This is for a load of 150 Ibs. per square foot, and the beams strained up to the maximum safe limit as given in the tables. With the same space the weight of the beams will vary directly as the load varies, consequently the weight of iron for any other required loading per square foot can be obtained by proportion from above rule. Example. A floor of 20 feet span is subject to a load of 150 Ibs. per square foot. The weight of the iron 20 2 beams will be F~^TK =5.33 Ibs. per square foot of floor, if 15" 2Q2 Beams are used, or if 12" Beams are used = ^ = 6.66 Ibs. per square foot. To these figures add the weight of ends built into the wall, which should be from 6" to 12" at each end, according to the span, etc. If the load to be sustained is 250 Ibs. per sq. foot, on 15" I beams the necessary weight becomes as 150 : 250 :: 5.33 Ibs. : 8.88 Ibs. per square foot. 64 WKOUGHT IKON AND STEEL. This rule applies only to the minimum section of any I beam. If the section is increased, the weight of iron required will also increase. By the above it will be observed that the deeper the beam used the less the amount of iron required, and such is the case as a general rule. But for short spans the use of the deep- est beams might require too wide a spacing to suit the covering of the floor. Then the best economy requires the adoption of a shallower and lighter beam. For brick arches for fire-proof floors it is usual to limit the rise or spring from 3 to 6 inches, in order to build in and conceal the tie rods, which should not be much if any above the center of the beam. For such flat arches the spacing of the beams should not exceed 6 feet, and if a single 4" course of brick is used, it is safest not to exceed 5 feet separation. Of course for arches of more rise and for other special purposes than indicated above, no such limitation is necessary. SPACING OF FLOOR BEAMS. The following rule gives the greatest distance apart that floor- beams can be placed to support safely any given load per square foot. Multiply the length of span in feet by the load in Ibs. per square foot. Find iu the table, page 40, the safe load in Ibs. for a beam of the size and length desirable to use. Divide this safe load by the product first found, and the quotient is the greatest distance in feet that the beams ought to be placed, center to center. Or Distance = -. w = Ibs. per square foot. L = length of span in feet. Example. A floor of 20 feet span with its full load will weigh 150 Ibs. per square foot. Different sizes of beams may be safely spaced as far apart as follows : For 15" 145 Ib. I Beams 80x150 = 10 ' 8 feet center to center - For 13 " 12 lb - l beams The tables on pages 56-62 show the greatest distance apart, center to center, that beams should be placed for a loading (in- cluding the weight of the floor itself) of 100, 150, 200, or 250 Ibs. per square foot. SPACING OF FLOOR BEAMS. 55 The deflections of the beams which are given .in the tables will be uniform for beams of the given spans so long as the spac- ing is proportioned according to the table. In the case of plastered ceilings or other circumstances where undue deflection might be injurious, it is considered good prac- tice to limit the deflection to about T ,- (T of the span. When the deflections exceed this amount, the corresponding loads in the table are printed in small figures. When the deflection is below this amount, the figures for the loads are in larger print. The proper spacing of beams for any load is inversely propor- tioned to the loads. Consequently the proper distance apart for beams for any load per square foot can be easily obtained di- rectly from the table as well as by the rule previously given. Rule. Multiply the distance given in the table by 150 and divide by the number of Ibs. per square foot required to be sus- tained. The quotient will be the greatest distance apart for the beams. Example. What is the greatest distance apart 8" 65 Ibs, I beams can be placed to support safely a load of 220 Ibs. per square foot, the beams having a clear span of 18 feet ? By the table the spacing for 150 Ibs. per foot is 3.3 feet ~* n 1 ^ > 2.25 /w feet, the distance required. [UNIVERSITY 56 WROUGHT IRON AND STEEL. PENCOYD o DECK BEAMS. Greatest distance between floor beams so that the bending stress on the beam will not exceed its maximum safe load. 1 | of LENGTH OP SPAN IN FEET. 1 fc if 8| O" -! ** 10 12 14 16 18 20 g o g H ni P* ^ es gs i o ft < DISTANCE BETWEEN CENTRES OP o 02 1 3 BEAMS IN FEET. 100 17.6 13.5 10.7 8.6 150 11.7 9.0 7.1 5.8 60 12 104 200 8.8 6.7 5.3 4.3 250 7.0 5.4 4.3 3.5 Deflection in Inches. i .28 .34 .44 .54 100 19.3 14.2 10.9 8.6 7.0 150 12.9 9.5 7.2 5.7 4.6 61 11 91 20 9.7 7.1 5.4 4.3 3.5 250 7.7 5.7 4.3 3.4 2.8 Deflection in Inches. .21 .29 .37 .46 .58 100 2-2.1 15.3 11.3 8.6 6.8 5.5 150 14.7 10.2 7.5 5.7 4.5 3.7 62 10 80 200 11.0 5.6 4.3 3.4 2.8 250 8.8 0J 4.5 3.4 2.7 2.2 Deflection in Inches. .16 .23 .32 .41 .52 .64 100 17.6 12.2 9.0 6.9 5.4 4-4 150 11.7 8.1 6.0 4.6 3.6 2-9 63 9 72 200 8.8 6.1 4.5 3.4 2.7 2-2 250 7.0 4.9 3.6 2.7 2.2 1 Deflection in Inches. .18 .26 .35 .46 .58 71 100 13.4 9.3 6.9 5.2 4-1 3-4 150 9.0 6.2 4.6 3.5 2-8 2-2 64 8 61 200 6.7 4.7 3.4 2.6 2- 1 1 -7 250 5.4 3.7 2.7 2.1 1 -7 1 -3 Deflection in Inches. .20 .29 .b9 .51 B5 to 100 9.2 6.4 4.7 3- 2-8 2 3 150 6.1 4.2 3.1 2- 1 -9 1 -5 65 7 52 200 4.6 3.2 2.3 1 1 -4 J-l 250 3.7 2.5 1.9 1- 1-1 ' Deflection in Inches. .23 .33 .45 & 75 92 100 6.8 4.7 3- 2- 2-1 1 -7 150 4.5 3.2 2- I- 1-1 1 1 66 6 42 200 3.4 2.4 1- 1- 1-1 9 250 2.7 1.9 1 1 8 7 Deflection in Inches. .27 .39 f> - 6 87 1 -07 100 4.5 3-1 2- ] 150 3.0 2-1 I- 1 67 5 34 200 2.2 1 1- 250 1.8 1-2 Deflection in Inches. .32 46 6 8 FLOOR BEAMS. 57 PENCOYD :Q DECK BEAMS. Figures in small type denote that the beams so placed will deflect more than J;- of an inch for each foot of span. LENGTH OF SPAN IN FEET. B O j. I 8^. H ft B| fe g H H 22 24 26 28 30 32 ^h^ E-- 1 a * g DISTANCE BETWEEN CENTRES OF ^ o ~ M s BEAMS IN FEET. o m 7.1 6.0 5- 4-4 3-8 3-4 100 4.8 4.0 3- 2-9 2- 2-2 150 3.6 3.0 2- 2-2 1 1 -7 200 104 12 60 2.9 2.4 2- ] -8 1 1-3 250 .65 .78 9 1-00 1-2 1-33 Deflection in Inches. 5.8 4 -8 4- 3-6 3- 2-7 100 3.8 o ft 3-2 2- 2-4 2- 1 8 150 el u.y 2.3 1 -9 1-6 1-4 1- 1-1 200 250 91 11 ol .71 84 99 1-15 1 ' 3 1-50 Deflection in Inches. 3-0 2-6 2-2 ] j. 100 150 2-3 1-9 1 I) 1 -4 1- 2ori 80 10 62 1 -8 1 -5 1-3 1 1 1 250 78 93 1-09 1-26 1 -4 Deflection in Inches. 3-6 3-1 2-6 2-2 100 2-4 2-0 1-7 1-5 150 1 ti 1-5 1 -3 1 1 200 72 9 63 J-5 1-2 1 -0 9 250 * 66 1-03 1-21 1-40 Deflection in Inches. 2-8 2-3 2-0 100 1 -9 1-R 1-3 150 1-4 1-2 1 -0 200 61 8 64 1-1 9 8 250 97 1-16 1-36 Deflection in Inches. 1-9 100 1-3 150 9 200 52 7 65 8 250 I'lO Deflection in Inches. 100 150 200 42 6 66 250 Deflection in Inches. 100 150 200 34 5 67 250 Deflection in Inches. 58 WROUGHT IRON AND STEEL. PENCOYD BEAMS. Greatest distances between centres of floor beams, so that the bending stress on the beam will not exceed its maximum safe load. CHART NUMBER. g Sis W pq &1 H M OD WEIGHT PER YARD, LBS. LOAD PER SQ. FT. OF FLOOR, LBS. LENGTH OF SPAN IN FEET. 10 12 14 16 18 20 DISTANCE BETWEEN CENTRES OF BEAMS IN FEET. 1 2 3 4 5 t% 6 15 Deflection 15 Deflection 12 Deflection 12 Deflection 10* Deflection 201 Deflection 1C* Deflection 200 in Inches. 145 in Inches. 168 in Inches. 120 in Inches. 134 in Inches. 108 in Inches. 89 in Inches 100 150 200 250 33.1 22.1 16.6 13.3 .27 25.3 16.9 12.7 10.1 .27 22.6 15.1 11.5 9.0 .34 16.6 11.1 8.3 ef ati O 38 F WEIGHT PER YARD, LBS. n o| z OB CHART NUMBER. 22 24 26 28 30 32 DISTANCE BETWEEN CENTRES OF BEAMS IN FEKT. 8-7 4-5 6-6 3-7 4-8 3-2 4-1 2-8 3- 2- I- 1- 1*4 100 150 200 250 112 Deflection 90 Deflection 90 Deflection 70 Deflection 81 Deflection 65 Deflection 65 Deflection 52 Deflection 10 in Inches. 10 in Inches. 9 in Inches. 9 in Inches. 8 in Inches. 8 in Inches. 7 in Inches. 7 in Inches. 7 8 9 10 11 12 13 14 2-7 78 2-3 92 1 -9 1-06 1-1 1-26 100 150 200 250 8-8 2-9 2-4 2-0 1-8 1- 78 92 l-O.'j 1'2 1*44 100 150 200 250 3-4 2-5 2-0 86 4-0 3-7 2-0 1 -6 86 4-0 2-7 2-0 1-6 97 3-3 2-2 1 -7 1-3 97 2-7 1-4 1-09 2-4 1-6 1-2 9 1-09 2-8 2-1 1-7 1-02 3-4 2-3 1-7 1-4 1-02 3-4 2-3 1-7 1-4 1-16 2-8 1-9 1-4 1-18 2-3 1 5 1-2 9 1-32 2-0 1 -3 1-0 8 1-32 2-4 1-8 1-5 1-21 2-9 2-0 1-4 1-2 1-21 2-9 1 -9 1-4 1-2 1-36 2-4 ! 6 1-2 1 -0 1-36 2-1 1-8 1-3 1-40 2-5 1-7 1*9 1-0 1-40 100 150 200 250 100 150 200 250 100 150 2UO 250 100 150 200 250 100 150 200 250 WEOUGHT IRON AND STEEL. PENCOYD BEAMS. Greatest distance between centres of floor beams so that the bending stress on beam will not exceed its maximum safe load. Figures in small type denote that the beams so placed will deflect more than ^ of an inch for each foot of span. t m p fc 15 16 17 18 19 20 21 22 SIZE or BEAM IN INCHES. WEIGHT PER YARD, LBS. : f LENGTH OP SPAN IN FEET. 10 12 14 16 18 20 DISTANCE FETWEEN CENTRES OP BEAMS IN FEET. 6 Deflection 6 Deflection 5 Deflection 5 Deflection 4 Deflection 4 Deflection 3 Deflection 3 Deflection 50 in Inches. 40 in Inches. in Inches. 30 in Inches. 28 in Inches . 18.5 in Inches. 23 in Inches. 17 in Inches . 100 150 200 250 8.4 5.6 4.2 3.3 .27 7.5 5.0 3.7 3.0 .27 E.O 3.3 2.5 2.0 .32 4.7 3.1 2.3 1.9 .32 R.8 3.9 2.9 2.3 .38 5.2 3.5 2.6 21 .38 2-8 2- 1 1 -7 62 3-8 2-6 1 -9 1-5 52 2-2 1-6 1-3 2-9 1-9 1-5 1-2 69 1-7 1-3 1-0 H7 2-3 1-5 1 -2 9 67 1-4 1 -0 8 1 -07 1-9 1-2 9 7 1-07 100 rso 200 250 100 150 200 250 100 150 201) 250 2-3 1-7 1 3 1-0 9 1-4 46 3-2 2- 1 J -0 63 2-4 1 -6 8 82 1 -8 1-2 8 1-04 1-4 9 5 1-29 1-2 8 1-3 46 1 -0 63 7 82 6 1 -04 5 1-29 100 150 200 250 100 150 200 250 100 150 200 250 100 150 200 250 2-4 1 -8 1-4 1-7 1-2 1-0 1-2 9 9 7 6 7 6 4 2-4 1 -6 1-7 1-2 8 7 6 1-0 40 2-0 1 -3 1-0 8 63 1-8 1 1 8 63 1-4 7 6 77 .7 a 4 77 5 79 1-0 7 5 4 1-05 0-8 5 4 3 1 -05 4 1 -03 8 5 4 3 1-37 8 4 3 2 1-37 3 1-31 LATERAL STRENGTH OF FLOOR BEAMS. 63 TIE RODS FOR BEAMS SUPPORTING BRICK ARCHES. The horizontal thrust of Brick arches is found as follows : 1.5 Wl? ^ = pressure in Ibs. per lineal foot of arch. W = Load in Ibs. per square foot. L Span of arch in feet R = Rise in inches. Place the tie rods as low through the webs of the beams as possible, and spaced so that the pressure of arches as obtained above will not produce a greater stress than 15,000 Ibs. per square inch of the least section of the bolt. Example. The beams supporting an arched brick floor are five feet apart, and the rise of the arches is six inches. The to- tal weight of floor and load equals 150 Ibs. per square foot. -^?- = 937.5 Ibs. pressure per lineal foot of arch. If one-inch screw bolts are used which have an effective section of -ft- square inches. Then .6 x 15,000 = 9,000 Ibs. which is the greatest load the bolt should be allowed to sustain, and 9 000 -^r = 9.6 feet = greatest distance apart of the bolts, or in 9o7.5 same manner we would find 5.3 feet, if inch tie rods are used. Ordinarily it wiJl be found necessary to limit the spacing of the tie rods to avoid excessive bending stress on the outer beams of the floor, or to prevent this bending stress being transferred to the walls of the building. The ability of the outer beams to resist the horizontal bending action caused by the pressure of the arches is determined as fol- lows : LATERAL STRENGTH OF FLOOR BEAMS. The resistance to bending of any I Beam or Channel bar, for a force acting at right angles to the web, or in the direction of the flanges, w = for I Beams - ft T W = f-T,, for Channels. 64: WROUGHT IRON AND STEEL. W = Safe distributed load in net tons. L = Length in feet between supports. F Width of flange in inches. / = Moment of inertia, axis coincident with web, see col. viii., pages 92-101. The above gives results which have been proved by experiment not to exceed one-third the ultimate strength of the beams. The formulae given properly apply to beams secured at each end only. If the beam is of considerable length requiring supports at several points, it can be considered as continuous (see page 75), and the formulae become, W = , for I Beams. 127 W = for Channels. Example. K 9-inch 70 Ib. I Beam forming the outer support for an arched brick floor has the tie rods at intervals of 6 feet. What evenly distributed horizontal pressure will it safely resist ? /=5.6 (see col. viii., page 92). F=4^ inches (see col. C, page 2). Then W= 15 Q * ^_ 6 - = 3.4 tons or 1,130 Ibs. per lin- eal foot of arch. Knowing the amount of the load W and requiring the distance L, Above equation becomes L? -==7-= in which W 1 = pres- W Jf sure or load on beam per lineal foot. .Example. An 8" 43 Ib. channel bar forms the end support for a system of brick arches having a span of 4 feet and 4 inches rise. How closely ought tie rods to be placed so that the chan- nels will not be overstrained ? The horizontal thrust per lineal foot of arch = 1 ' 5 x ^ x 16 = 900 Ibs. or .45 tons. I - 2.17. F=W*. 12 x 2.17 BEAMS SUPPORTING BRICK WALLS. 65 It will generally be found that an angle bar makes a better and more economical support for the arches on the side walls than either an I beam or channel. The resistance to bending of an angle is readily found by the rule given on page 69. W = - - = safe distributed load for a non-continuous Li beam. 1 4A.D W -4-= = safe distributed load for a continuous beam. Li And as before L z = 1AAD A being the sectional area in square inches, and D the width or size of the angle in inches. Applying this rule to the last example, and considering the 8" channel replaced by a 4" x 4' x i" angle whose area = 3. 75 square inches. 1.4 x 3.75 x 4 .45 = 46 . 6 or L = 6 . 8 feet between centers of boits. Stress on bolts 900 x 6.8 = 6,120 Ibs. To resist this |" would be the proper diameter of the screw. BEAMS SUPPORTING BRICK WALLS. If the wall has no openings and the bricks are laid with the usual bond, the prism of wall that the beam sustains will be of 66 WBOUGHT IRON AND STEEL. a triangular shape, the height being one-fourth of the span. Owing to frequent irregularities in the bonding, it is best to con= sider the height as one-third of the span. The weight of brick work for each inch of thickness, is about 10 Ibs. per square foot. Therefore the weight of the triangular mass of brick that the beam supports is found as follows : span, x o~~ in feet x 10 times the thickness of the wall in inches = weight in Ibs. ; or reducing above to its more concise form, W = Weight in Ibs. supported by the beam. t Thickness of wall in inches. s Span of beam in feet. The greatest bending stress at the center of the beam, result- ing from a brick wall of above shape, is the same as that caused by a load one-sixth less concentrated at the center of the beam. Example. What beam will be required to span an opening of 16 feet, and carry a solid brick wall 8 inches thick, the beam not to be strained more than one-third of its ultimate strength ? Weight of wall by the rule. W = 1( * ^ 256 rr 3,4 1 3 Ibs. Considering the load as in middle of beam, it would be five- sixths of above = 2,845 Ibs., or 5,690 Ibs. if evenly distributed. By our table page 43, a 7" I beam 52 Ibs. per yard, comes near- est to what is required, its greatest safe distributed load being 3.5 tons. The deflection under this load will be about .45 of an inch, found as described on page 89. If a wall has openings such as windows, etc.. the imposed weight on the beam may be greater "than if the wall is solid. For such a case consider the outline of the brick, which the beam sustains, to pass from the points of support diagonally to the outside corners of the nearest openings, then vertically up the outer line of the jambs, and so on if other openings occur above. If there should be no other openings, consider the line of imposed brick work to extend diagonally up from each upper corner of the jambs, the intersection forming a triangle whose height is one-third of its base, as described at beginning. FORMULAE FOB ROLLED IRON BEAMS. 67 APPROXIMATE FORMULA FOR ROLLED IRON BEAMS. The following rules for the strength and stiffness of rolled iron beams of various sections are intended for convenient ap- plication in cases where strict accuracy is not required. The rules have been derived from the authoritative formula?. Those for rectangular and circular sections are correct, while those for the flanged sections are limited in their application to the standard shapes as given in our tables. They will be found to give results which have been proved by experiment to be suf- ficiently accurate for practical purposes. When the section of any beam is increased above the standard minimum dimensions, the flanges remaining unaltered, and the web alone being thick- ened, the tendency will be for the ultimate load as found by the rules to be in excess of the actual, but within the limits that it is possible to vary any section in the rolling, the rules will apply without any serious inaccuracy. IN THE TABLES OF FORMULAE Column I. indicates the cross section of the beam. Column II. gives the ultimate load applied at the center of a beam supported at each end. Column III. gives the ultimate load uniformly distributed over a beam supported at each end. Column IV. indicates the deflection under any load, w (not ex- ceeding one-half the ultimate load) at the middle of the beam. Column V. gives the deflection for a load uniformly distributed. SAFE LOADS. The ultimate load given in the tables is defined on page 32. One- third of this should be accepted as the greatest safe station- ary load, and from one-fourth to one-sixth of the same when a moving or fluctuating load is imposed, according to the way it is applied, cr the degree of stiffness required. See table, page 34. 10 A = WEIGHT PER YARD IN LBS. The area, A, of any cross section of wrought iron may be ob- tained by dividing its weight per yard by 10 ; and vice versa, its weight per yard may be found by multiplying its area in square inches by 10 ; e.g. the area of a beam weighing 50 Ibs. per yard is five square inches. 68 WEOUGHT IBON AND STEEL. * a ?.! FORMULA FOB WROUGHT IRON BEAMS. 9 s ^ SJ ^ -^ Q ^ 00 o* CD "^ (^ o H 1-1 OJ W CO w "^ CO ^ fc I 5t= i |\ _ /I IT "\| 70 "WROUGHT IEON AND STEEL. EXAMPLES CALCULATED FROM PRECEDING TABLES. SOLID RECTANGULAR SECTIONS. Example 1. To find the breaking load for any solid rectan- gular beam loaded in the middle. ~r C = Solid rectangular bar, 2 inches wide, 4 inches j* deep and 10 feet between supports. Then, from For- 1 mula No. 1 , we have * x 4.16 tons breaking lv load in middle of beam. Example 2. To find the uniformly-distributed breaking load for same beam. Formula No. 2. ?' 6 x 8 = 8.32 tons breaking load uni- formly distributed. Example 3. To find the deflections for above beam under the greatest safe loads ; viz., one-third breaking loads. Formula No. 3. *' 39 * =0.36 inches, for a load of 1.39 oO x 8 x lo tons in middle. Formula No. 4. - 77 x 10 ? = 0.45 inches, for a load of 2.77 48 x 8 x 16 tons distributed. HOLLOW RECTANGULAR SECTIONS. Example 4. To find the breaking loads for any hollow rec- tangular beam supported at both ends. Let be a hollow rectangular section, 4 inches wide, "t 8 inches deep, external dimensions ; 3 inches wide, 6 inches deep, internal dimensions; 15 feet between sup- ports. Formula No. 5. _K*JL9- < 18 * 6 U = 13.83tons,bre a k- 15 ing load in middle ; and multiplying this result by 2, we have 25.66 tons for the breaking load uniformly distributed. EXAMPLES FROM PRECEDING TABLES. 71 Example 5. To find the deflection of this beam with three tons in middle ; also with six tons distributed. flection with three tons in middle. Formula No. 8. J-.., inehes de . flection with six tons distributed. SOLID AND HOLLOW CYLINDERS. The preceding examples for rectangles will apply to the circular sections by merely sub- stituting the proper co-efficients as given in Formulae 9 to 16 inclusive. EVEN-LEGGED ANGLES AND TEES. Example 6. To find the breaking loads for an even-legged angle or tee, used as a beam supported at both ends. Weight, 37 Ibs. per yard or 3.7 square 't, inches section; 12 ft. between supports. Formula No. 18. 2 ' S * tons breaking load uniformly distributed, or 1.73 tons breaking load in the middle. Example 7. To find the deflection of the above beam under a load suspended from the middle of the beam. Load = 1500 Ibs. = . 75 tons. Formula No. 19. ' 6 = - 64 inches deflection - Theoretically an angle has the same transverse strength as a tee of the same dimensions. But owing to the difficulty of dis- posing the load as symmetrically on the angle as on the tee, the latter shape generally yields better results by experiment. 72 WROUGHT IRON AND STEEL. CHANNEL BARS. Example 8. To find the breaking loads for a channel bar used as a beam supported at both ends. Channel bar 9 inches deep, 70 pounds per yard ; 7 square inches section, 14 feet between supports. Formula No. 22. --*^ - = 17.1 tons distributed breaking load, or half this weight will be the breaking load in the middle. Example 9. To find the deflection of above beam under greatest safe distributed load. 17.1 3 = 5.7 tons greatest safe distributed load. Formula No. 24. j>.7 x 2744 _ g g ^ deflection. 80 x 7 x 81 I BEAMS. Example 10. To find the breaking loads for an I 'beam, loaded in the middle and supported at both ends. A 15" I beam, 200 Ibs. per yard, 20 square inches area, 20 feet between supports. Formula No. 29. 2-1 x 20 - = 31 . 5 tons middle breaking load ; one-third of which (10.5 tons) will be greatest safe load in middle, or twice this (21 tons) equals greatest safe load distributed. Example 11. To find the deflections for the same I beam under the above greatest safe loads. Formula No. 31. = .33 inches under a load of 56 x 20 x 225 10.5 tons in the middle. Formula No. 32. 21 * 800( L, g = .41 inches under a load of 90 x 20 x 225 21 tons uniformly distributed. Although the preceding rules for I beams and channels give results which are substantially correct for all the standard sec- EXAMPLES FROM PRECEDING TABLES. 73 tions as ordinarily rolled, yet they are not strictly accurate, and not applicable to the heavier-built beams, whose flanges are much larger, relatively to the web, than is the case in the aver- age rolled beams. For such cases, the following formula is , Q.QA'D' + l.2a'd f , , . , , . correct. = breaking load in middle of beam. A' = Area of one flange. D = Depth between centres of flanges. a = Area of web. d = Depth of web. For example, a beam 20 inches deep, flanges 8" x 1", web " - , thick, 20 feet between supports, 6.6 x 8 x 19" + 1.2 x 4.5 x 18 55 tons 20 breaking load in middle of beam ; whereas the Rule in Table for Rolled Beams would give a similarly placed load of 2.1 x 20.5 x 20 20 = 43 tons. When the load is concentrated away from the centre of beam, the ultimate load will be to the load at centre as the square of half the span is to the product of the segments formed by posi- tion of load. Example. A beam 20 feet between supports has its load placed 5 and 15 feet respectively from each end : the breaking load at that point is to the calculated breaking centre load as 100 is to 75. BEAMS HAVING NO LATERAL SUPPORT BETWEEN BEARINGS. If beams are us?d without any support sideways, the ten- dency to fail, by lateral bending of the top flange, will increase with the length of the beam ; and, in such cases, it is better to limit the application of the preceding rules to beams whose lengths do not exceed 20 times the width of the flange, gradually increasing the factor of safety for longer beams ; so that, when 74 WROUGHT IRON AND STEEL. the beam reaches a length equal to 70 times the width of the flange, the greatest safe load would be about one-sixth of the calculated breaking load, or the proper factor of safety for the latter beam would be double that for the former. (See page 36.) CANTILEVER BEAMS. The application of the preceding rules to overhanging beams fixed at one end and free at the other, is best indicated by sup- posing a beam with both ends supported to be inverted, and the reaction of the supports considered as the positive load. w w / It is then evident that a beam, A C (see above illustration), both ends supported, will be strained with a middle load, W, in an equal manner to a cantilever, A B or B C, of half the length of A G and having a similar section, and bearing one-half the load(orf) at its end. EXAMPLES FOR CANTILEVER BEAMS. A rectangular bar, 6" x 2", built into a wall and projecting eight feet. For load concentrated at its end, take one- fourth the co-efficient in Table for Beams with both ends supported and load in middle. =2.9 tons ultimate load. Deflection under one-third of above, or say nine- tenths of a ton ; substituting one-sixteenth of the co-efficient for 9 x 512 deflection when load is in middle. ~ = 0.56 inches deflection at end. A 12-inch I beam, 15 square inches section, extends 10 feet beyond a rigid support. For a load evenly dis- tributed, take one-fourth the co-efficient for a beam supported at both ends, bearing a distributed load. 1.05 x 15 x 12 ->y * .1 u i i j j- x M j. i -^ = 18 . 9 tons breaking load distributed. EXAMPLES FKOM PBECEDING TABLES. 75 For deflection under five tons distributed, substitute one-sixth of the co-efficient for deflection in Rule for Beams supported at both ends with load in* middle. -^ = 0.25 inches deflection at end of beam. CONTINUOUS BEAMS. When a beam is continuous over several supports, or when both ends are as rigidly secured as is necessary at the fixed ends of a cantilever, the beam is practically in the same condition as a non-continuous beam of shorter span. When the load is applied at the middle of the span, the ulti- mate breaking load of a continuous beam is equal to twice that for a non-continuous beam similarly loaded and of the same length and section. When the load is evenly distributed, the ultimate load for a continuous beam is 1.5 times greater than the ultimate load for a non-continuous beam under the same conditions and of the same length and section. The deflection of a continuous beam is one-fourth that of a non-continuous beam when similarly loaded. To find the strength and stiffness of continuous beams, take the rules given for non -continuous beams and alter the co-efficients in the proportions stated. EXAMPLES FOR CONTINUOUS BEAMS. A 4-inch I beam of three square inches section is continuous over supports twenty feet apart. To find the greatest safe load uniformly distributed, and corresponding deflection, take 1.5 times the co-efficient for a similar non-continuous beam. ^ = 3 . 78 tons breaking load, or 1 . 26 tons safe distrib- uted load. For deflection, take four times the co-efficient for the same class of non-continuous beam. ^ i ^ = 0.58 of an 360 x 3 x 16 inch deflection. For a continuous beam bearing load in middle, take twice the 76 WROUGHT IRON AND STEEL. co-efficient given for the strength of a similarly loaded non-con- tinuous beam, and, for deflection of the former, take four times the co-efficient given for the % latter beam. It will be observed that these rules apply only to the interme- diate spans of continuous beams, as, owing to the failure of con- tinuity at one end of each outer span, the conditions are altered. If, however, the outer ends of a continuous beam overhang the end-supports from one-fifth to one-fourth of a span, and bear the same proportion of load as the parts between supports, then the outer spans may be of same length as the intermediate spans, subject to the same load, and the strength and stiffness are de- termined by the same rules ; otherwise, the outer spans ought to be only four-fifths of the length of the intermediate spans when the load is distributed, or three-fourths of the same when the load is concentrated in the middle ; or, if the lengths of spans are all alike, the loads on outer spans ought to be reduced in the same proportion. The following table exhibits the relative proportions of strength and stiffness existing between the various classes of beams when they have the same lengths and uniform cross sections ; the deflections being comparative figures for the same loads. KIND OF BEAM. Breaking loud as Deflection as Fixed at one end loaded at the other l 16 Fixed at one end load evenly distributed. . . * 6 Supported at both ends load in middle 1 1 Supported at both ends load evenly distrib- uted 2 | Continuous beam load in middle 2 i Continuous beam load evenly distributed. . . 3 R ft The breaking load and deflection of a beam supported at both ends and loaded in the middle have been taken as the units in EXAMPLES FROM PRECEDING TABLES. 77 the preceding table, and the proportional strength and stiffness of similar beams under different conditions given to find the proper co-efficient for estimating the strength and stiffness of the beam required, it is necessary to alter, in the given propor- tions, the co-efficient for the same beam when supported at both ends and loaded in the middle. CHANGES OF CO-EFFICIENTS FOR SPECIAL FORMS OF BEAMS. For beams of the character denoted in list below, change the co-efficients in table of formulae, pages 68-69, in the ratio given. For concentrated loads and distributed loads respectively, change the co-efficients given for the same kinds of loads in the table. KIND OF BEAM. CO-EFFICIENT FOR ULTIMATE LOAD. CO-EFFICIENT FOB DEFLECTION. Fixed at one end, loaded at the other. One-fourth (\) of the co-efficient of table. One - sixteenth (A-) of the co- efficient of ta- ble. Fixed at one end, load evely distributed. One-fourth (\) of the co-efficient of table. Five - forty- eighths (-&) of the co-efficient of tables. Both ends rigidly fixed, or a continuous beam, with load in middle. Twice the co-effi- cient of table. Four times the co-efficient of table. Both ends' rigidly fixed, or a continuous beam, with load evenly distributed. One and one-half (1?) times the co- efficient of table. Four times the co-efficient of table. 78 WKOUGHT IBON AND STEEL. BENDING MOMENTS AND DEFLECTIONS FOR BEAMS OF UNIFORM SECTION. W= Total load. L = Length of beam. E = Modulus of elasticity. / = Moment of inertia. FORM OP BEAM AND POSITION OF LOAD. Maximum bending moment. Maximum shearing stress. Deflection. Beam fixed at one end loaded at the other : + r\ F|G - 1 ^ ^^N. at point of support at point of support at end of beam i (w) ~ 37" Draw triangle having A = WL. Vertical lines give bending moments at corresponding points on the beam. Beam fixed at one end, load uni- formly distributed : 7 N. | ! G. 2 at point of support 2 ' at point of support at end of beam _ WL* ^ L o o o o o_o Draw pnrabola having A = k Ordinates give bending moments at corresponding points on the benm. Beam supported ed in the middle : at both ends, load- ,/j v FIG. 3 > IV 1 T\ at middle of beam _ WL 4 ' at point of support = "2" at middle of beam '._ WL* <_ L (g) - Draw triangle having A = Vertical lines give bending moments at corresponding points on the beam. BENDING MOMENTS AND DEFLECTIONS. 79 BENDING MOMENTS AND DEFLECTIONS FOR BEAMS OF UNIFORM SECTION. W= Total load. L = Length of beam. E = Modulus of elasticity. / = Moment of inertia. FORM OP BEAM AND POSITION OP LOAD. Maximum bending moment. Maximum shearing stress. Deflection Beam supported at both ends, load uniformly distributed : x^T^x' 4 at middle at point of at middle / ^ ' ^\v of he-am support of beam A i\ WL W WL 3 / 1 ! ! \ 8 ' ~ 2' ~ 76.8.E7' WL Draw parabola having A = o Ordinates eive bending moments at corresponding points on the beam. Beam supported at both ends, load concentrated at any point : at point of support next to a / \v. FIG> 5 _ Wb at position of load L ' at position of load A ' ^^\^ Wab at point of a 2 6 2 W S\ j ! ' !\^ L support ~ 3EIL' ;:::: 1 ~ " -H _ Wa Wab Draw triangle having A = . L Vertical lines give bending moments at corresponding points on the beam. 80 WKOUGHT IRON AND STEEL. BENDING MOMENTS AND DEFLECTIONS FOR BEAMS OF UNIFORM SECTION. W = Total load. L = Length of beam. E = Modulus of elasticity. / = Moment of inertia. Beam supported at both ends, with concentrated load at various points : R FIG. 6 Draw (by 5) the triangles having vertices at C, D and E, the verticals rep- resenting bending moments for loads w 1 , w* and w 3 , respectively. Extend FC to P, GD to R, and HE to S, making each long vertical equal to the sum of the bending moments corresponding to its position. That is, FP = FO + FI+ FJ. GR = GD + GL + GK. And HS = HE+ HN+ HM. Verti- cals drawn from any point on the polygon, APBSB to AB, will represent the bending moments at the corresponding points on the beam. Beam rigidly secured at each end, and loaded in the middle. Or the inter- mediate spans of a continuous beam, equally loaded in the middle of each span : A FIG. 7 <- L Points of contraflexure at #, ce, where Moment = 0. Distance of x from either support = . Equal moments at middle and ends = . WL* WL Deflection j-' and at ends draw verticals BB', each Draw a triangle having A = ^p' join BB'. The vertical distances between BB' and the sides of the triangle, represent the moments for corresponding points en the beam. BENDING MOMENTS AND DEFLECTIONS. 81 BENDING MOMENTS AND DEFLECTIONS FOR BEAMS OF UNIFORM SECTIONS. W = Total load. L = Length of beam. E = Modulus of elasticity. / = Moment of inertia. Beam rigidly secured at each end with load uniformly distributed. Or the intermediate spans of a continuous beam bearing a uniformly dis- tributed load on each span : FIG. 8 Points of contraflexure x, x, where moment = 0. Distance of x from either support = .21 L. Draw parabola having A = -5 Draw verticals B, E', each equal to O TTTr -p join BE', The vertical distances between BE' and the curve of the pa- rabola represent the moments for corresponding points on the beam. WL Maximum moment at points of support = -r~-. Moment at middle of beam = WL Maximum deflection at middle of beam WL* 307. 27* 82 WROUGHT IRON AND STEEL. BEAMS FOR SUPPORTING IRREGULAR LOADS. When a beam has its load unequally distributed over it, the proper size of the beam can be determined by finding the maxi- mum bending moment and proportioning the beam accordingly. Equilibrium is obtained when the bending moment is equal to the moment of resistance. That is, when the external force mul- tiplied by the leverage with which it acts is equal to the strength of the material in the cross section of the beam multiplied by the leverage with which it acts. The ultimate moment of resist- ance for a wrought-iron beam of symmetrical form is 42000 / 84000_/ - depth d d = depth of beam in the direction in which the force acts. 1= the moment of inertia about the axis at right angles to the direction of the force. The greatest sai'e moment of resistance as adopted in our tables is one-third (j) of above, ^_ 280007 M I ~ ' 38000"^ The co-efficient to be changed according to the factor of safety desired. The rule would thus be ' - = - Co-efficient d RULE FOR BEAMS BEARING IRREGULAR LOADS. Find by the methods described in preceding article the maxi- mum bending moment in inch-lbs. for the loads. Divide the moment by the proper co-efficient as described above. Find in the tables, pages 92-96, a beam whose inertia divided by its depth is not less than this quotient; which will be the beam re- quired. In some instances the maximum bending moment can be most readily found by the use of diagrams, as described in the succeed- ing article. When this is done use any convenient scale, making all loads RULES FOB BEAMS BEARING IRREGULAR LOADS. 83 and all distances respectively of the same denominations. The maximum bending moment can then be measured to scale. Example. An I beam 8 feet long is to be fixed at one end and loaded at the other with 5,000 Ibs. and carrying also an evenly distributed load of 8,000 Ibs. What size of beam should be used so as not to ba strained over one-third of its ultimate capacity ? Moment for end load = 5,000 x 96 = 480,000 inch-lbs. " distributed load = 8>00 ' x 96 = 384,000 " A __ Total = 864,000 " For one-third of ultimate the co-efficient will be 28,000. 864.000 J 28,000 - ~d By Column VII., page 92, for a 12" 168 Ib. I beam, J = 371.98, which divided by 12 = 30.99; or a 15" 145 Ib. I beam, -5- =34.7. The latter beam would be stronger and lighter. In the following example the maximum bending moment can be very readily obtained by a diagram as described in Fig. 6 of the preceding article. Example. A beam 20 feet long between supports, will carry three loads, which we will call A, B, and C. A 4,000 Ibs. and is 4 feet from one end of the beam. C 6,000 Ibs. and is 3 feet from the other end of the beam. B = 5,000 Ibs. and is 5 feet from C and 8 feet from A. What beam is best to use for above, not strained over one- fourth of the ultimate ? Describe the diagram as per Fig. 6, when the following bending moments in ft. -Ibs. will be ob- tained. WROUGHT IRON AND STEEL. At point A For load 4.. 12,800 B.. 8,000 C.: 3,600 At point B For load B.. 24,000 A.. 10,800 C. . 6,400 At point C For load C. . 15,300 B.. 8,900 A.. 2,400 Total 24,400 Total.... 41,200 Total. . . . 26,600 The maximum moment at B = 41,200 ft.-lbs. or 494,400 inch. Ibs. For one-fourth of ultimate strength co-efficient = 21,000. 494.400 21,000 = 23.5 = V By table on page 92, for a 12" 120 Ib. I beam L = 22.74, be- d ing slightly deficient. A 12" 125 Ib. I beam will be ample. If more lateral stiffness is required than a single beam affords, use a pair of channels separated and braced horizontally. Two 12" 75 Ib. channels -j = 23.6, would suit above purposes. NOTE. The tables of elements, except where otherwise speci- fied, are calculated for dimensions in inches and weights in Ibs., consequently in examples of above character it is necessary to obtain bending moments in inch-lbs. BEAMS SUBJECT TO BOTH BENDING AND COM- PRESSION. When a beam is subjected to bending action and simulta- neously has to act as a strut by resisting compression, the stress of the fibres of the beam in tension will be relieved and those in compression correspondingly augmented. No general rules can be given for such conditions, as every particular case requires its own proper determination. The fol- lowing methods, though not strictly correct, will give safe re- sults for some simple forms of trussed girders, etc. (1.) When the beam is subject to compression but is so con- fined laterally that it cannot fail by bending like a strut. BEAMS SUBJECT TO BENDING AND COMPRESSION. 85 Rule. Find the section of beam required to resist bending, then allowing from 10,000 to 15,000 Ibs. per square inch of sec- tion for the compression, according to the factor of safety used, add the area so found to the first area, which will give the sec- tion of required beam. Example. What I beam is required to span an opening of 30 feet, to be trussed 3 feet deep between centres in the manner illustrated in Fig. 6, page 165? (this trussed beam carries a brick wall which weighs 500 Ibs. per lineal foot, but which braces the beam from yielding sideways), the beam to be proportioned for a safety factor of four ? Here the beam can be considered as composed of two separate beams, reaching from the centre to each end, each being 15 feet long, carrying a distributed load of 15 x 500 = 7,500 Ibs., and subject to a compression resulting from the trussing of 18,750 Ibs. Our approximate tables for beams, on page 69, will be found most convenient for such calculations as the above, and are sufficiently accurate for practical purposes. For I beam, dividing co-efficient by 4 we have ' = safe distributed load = 3. 75 tons. By trial we find for an 8" 65 Ib. I beam ltQ *' 5 *- = 3.64, 10 or nearly correct. For the compression, allowing 12,500 Ibs. per square inch, we require l square inches. Therefore an 8" I beam, 8 square inches section, will be safe. If desirable to use a deeper, lighter beam, try a 9-inch beam 75 Ibs. per yard ; allowing 1| square inches for the compression, we have a section of 6 square inches remaining ; = 3.78. 15 The latter beam being both stronger and lighter than the 8- inch. (2.) When the beam is subject to compression and is liable to fail like a horizontal strut by lateral flexure. Rule. Consider first the resistance as a strut and then make the necessary increment of section to resist the bending stress, remembering that if the addition is made to the flanges then only flange stresses have to be considered, but if the increased 86 WROUGHT IRON AND STEEL. area is obtained by thickening the web of I beam or channel sec- tions, then the additional area so obtained should be treated as a rectangular section whose thickness is the amount added to the web, and whose depth is the depth of the beam. Example. A. trussed girder of the form exhibited in Fig. 8, page 165, is a box section made up of two channels separated with flanges outward, and plated top and bottom. The whole girder is 30 feet long and is loaded 1,000 Ibs. per lineal foot. The com- pression resulting from the trussing is 25,000 Ibs. The structure has no lateral bracing. What will be safe proportions for it, the stresses not to exceed of the ultimate ? It is evident that we have to consider it as a flat-ended strut 30 feet long liable to fail horizontally, and also as a series of 3 beams each 10 feet long and loaded with 10,000 Ibs. evenly dis- tributed. Trying 2 lightest 5" channels, each 2.27 square inches section, separated 5" so as to be covered by 9" plates, we have (omitting the plates in this calculation,) the radius of gyration around vertical axis (see page 110) =.3.25 inch- l es, - = 110, one-fifth of ultimate (by Table I, page 118) - 5,600 Ibs. per square inch, or 5,600 x 4i = 25,200 Ibs. safe resistance, which is ample. Now proportioning the plates to resist the bending strain we have maximum bend- 1 9ft v 1 000 ing moments (see page 78), ~ -' = 150,000 inch-lbs. o The plates act with a leverage equal to the depth of the chan- nel, viz., 5"; '- = 30,000 Ibs. tension on top or compres- 5 sion on bottom plate, which, allowing for 10,000 Ibs. per square inch, and allowing for loss by rivets, will require a plate f" thick. (3 ) Taking the last example, if it was desired to form the sec- tion out of a pair of channels latticed top and bottom with no cover plates, we would have to consider the section added to the channels (being on the web alone), as a simple rectangular sec- tion. By the formula on page 69, approximate rules, we find that such a section only 5" deep would require a thickness of 3.8 inches, which is impracticable ; we have therefore to use deep- ELEMENTS OF PENCOYD STRUCTURAL SHAPES. 87 er and heavier channels. Trying 8" channels separated as be- fore 5 inches, with flanges outward, and having radius of gyra- tion for the pair around vertical axis = 3.4, = 106. Safe load 90 nftft ^ J> 1W = 5,800 Ibs. per square inch. As the compression is 25,OCO 5 Ibs., there is required 4.8 square inches for this purpose. By formula 2, page 68, - 52 x ^ ea x 8 _ 5 tons, from which is found the area required to resist bending 12 square inches. 12 4- 4.3 = 10.3 square inches for 2 channels, or the heaviest 8 channels 80 Ibs. per yard would be required. By the same method we find 10" channels 68 Ibs. per yard, will answer the purpose, or our lightest 12" channels 60 Ibs. per yard, will exactly meet the requirements and be the lightest channel that can be used in the manner proposed for the pur- pose. In cases where the load is concentrated at the truss points, there being no bending stress, the resistance as a strut has only to be considered, and when braced laterally the strut length is reduced to the distances between bracir.g. ELEMENTS OF PENCOYD STRUCTURAL SHAPES. In the following tables, pages 88, 91, various properties of rolled structural iron are given, whereby the strength or stiff- ness of any shape can be readily determined. SYMBOLS. I = Moment of inertia. E Modulus of elasticity. W = Load on beam in net tons. w = Load on beam in pounds, R = Radius of gyration. A Total area of cross section. L Length between supports in feet. I = Length between supports in inches. 88 WROUGHT IRON AND STEEL. Column I. Chart number. Columns III. to VI. Details of the sectional areas in square inches. The flanges being taken the entire width of section, and the web considered between the flanges. Columns VII. and VIII. The moments of inertia, respectively, at right angles to and parallel with web of beam. In all cases the axes referred to pass through the centre of gravity of the cross-section, as illustra- ted at the head of each table. Columns IX. and X. The' radii of gyration in inches A/ . r A When R 2 is required, simply divide the moment of inertia by the area of the section. The values of / and R have all been carefully calculated by the formulae given on pages 102-111. The tables give the value of 1 for the minimum section of each particular shape, but the section can be increased in area up to the maximum limit given in the descriptive tables, pages 2-12, and the value of / can be readily obtained for any enlarged section as described on pages 106-108. Column XI. Co-efficient for the greatest safe load evenly dis- tributed over the beam. This is the calculated load in net tons for a beam of the given size and section, one foot long, and is derived from the formula -- = -, which gives re- 8 depth of beam suits averaging one-third of the ultimate strength of the beam. The safe distributed load for any beam of the size and section given in Columns II. to VI. can be found by dividing the correspond- ing co-efficient in column XI. by the length of the beam between supports, in feet. Example. The greatest safe load that can be evenly distrib- uted on a beam 10 inches deep having a sectional area of 9.04 "1 Qft A. square inches and spanning 12 feet is 10 ' = 11.5 tons. ELEMENTS OF PENCOYD STRUCTURAL SHAPES. 89 If -the load is concentrated in the middle of the beam, one- half this result, or 5.75 tons, is the greatest safe load. If the sectional area of the beam is increased, find the moment of inertia for the increased section as described on page 106, and the co-efficient for a distributed safe load = - - -3- _ . depth of beam Example. The 10" beam taken in last example, 9.04 square inches area, is increased to 10.6 square inches section. The in- ertia of enlarged section is found as per formula on page 106, 1.56 = (increase of area) x 100 = (square of depth) 10 - - - ~j - = - = - - = lo. + 1 4o . o I/O (inertia, col. vii., page 92,) 161 .3 or moment of inertia desired. Co-efficient for safe load = 161> ^ > -^ = 150.5. Dividing this co-efficient by the span in feet (12), gives -^f~ = 12.54 tons as \4i the maximum safe load distributed, or 6.27 tons in the middle of the beam. Lateral Flexure. It will be noted that when subjected to such loads as above obtained, the beams are presumed to be secured from bending sideways, and it will be safest to limit the applica- tion to beams secured laterally at intervals, in length not ex- ceeding twenty times the width of flange. See preface to tables of safe loads for beams, page 36. Columns XII. and XIII. Deflections. The figures in the tables are the calculated deflections for beams of the sizes and sections given, one foot long between bearings and supporting a load of one ton. They are derived by means of the formulae X = deflection for load in middle of beam. ^ = deflection for load evenly distributed. 7o . The modulus of transverse elasticity is assumed as 26,000,000 Ibs. The elasticity of rolled iron is somewhat uncertain, it is frequently quoted as high as 29,000,000 Ibs., and experiments on bars of exceptionally stiff iron will often give results much in excess of this. But recent experiments on rolled beams show that 26,000,000 Ibs. is a fair average for this form of wrought iron. See page 19. 90 WROUGHT IRON AND STEEL. The deflection of any beam of the sectional area given in cols. IV. to VI., and loaded within the elastic limit, is found by mul- tiplying the corresponding co-efficient in cols. XII., XIII., by the weight in tons and the cube of the length in feet. Example. A. 12" I beam, 11.95 square inches section, 13 feet between supports, carries an evenly distributed load of 15 tons. Deflection- .0000063 x 15 x 13 3 = .207 inches. If the sectional area of this shape is increased, the value of 1 for the enlarged section must be found as described in previous example. By reducing the formulae for deflection to their sim- plest forms we obtain : 1 1 r T :< = deflection in inches for load in middle. 3627 "WJ ' J =-^4- = deflection in inches for distributed load. 5807 Example. The 12" beam in previous example 11.95 square inches area, is increased to 13.8 square inches The inertia of enlarged section is found as per formula, page 106. 1 . 85 (increase of area) x 144 (square of depth) _ -i n ** * l~ * * ~" inertia, col. vii., page 92, = 295.06, or moment of inertia desired. For beams of the same depth, but of any sectional area, thts deflection remains uniform so long as the loads bear a uniform ratio to the strength of the beam. For this reason, the single column of deflections applies to any section of the same size of beam, in the tables of safe loads. Column XIV. Maximum load in tons. There is a limit in the length of beams at which the rule for safe loading ceases to apply. This point is reached when the load attains the safe limit of resistance offered by the web of the beam against crippling. The maximum load can be placed on any beam shorter than the length indicated, but must not be exceeded. It is obtairied by Gordon's formula, taking 6 tons per square inch as the safe resistance of wrought iron to crushing. ELEMENTS OF PENCOYD STBUCTUBAL SHAPES. 91 W = 6^ d = depth of beam, -j , P t thickness of web. 3000^ I = d x secant 45 (P = 2cf). Example. An 8" 65 Ib. beam has a maximum load of 10.46 tons, which corresponds to the greatest safe load on a beam of this section, 7.7 feet between supports, if the load is distributed, or 3.85 feet if the load is at middle of beam. If this shape is in- creased to 7-i square inches area, having a web -fc" thick, then maximum safe load becomes 6 " x 8 " x -i 92 WROUGHT IRON AND STEEL. ELEMENTS OF FENCOYD BEAMS. r I. II. III. IV. V. VI. VII. VIII. CHART NUM- BER. 1 SIZE IN INCHES. WEIG'T PER YARD. AREAS IN SQUARE INS. MOMENT OP INERTIA. Flanges Web. Total. Axis A. B. Axis C. D. 15 200 11.86 8.04 19.90 682.08 28.50 2 15 145 8.97 5.58 14.55 521.19 16.91 3 4 5 12 12 m 168 120 134 10.66 7.42 9.57 6.23 4.53 3.87 16.89 11.95 13 44 371.98 272.86 241.63 23.19 12.22 19.00 5* 104 108 7.33 3.50 10.83 195.42 12.45 6 10* 89 5.91 3.03 8.94 162.26 8.34 7 10 112 7.23 3.94 11.17 173.58 10.64 8 10 90 6.29 2.75 9.04 148.31 8.09 9 9 90 6.15 2.92 9.07 118.81 8.44 10 9 70 4.77 2.21 6.98 94.44 5.59 11 8 81 5.58 2.56 8.14 83.93 7.23 12 8 65 4.50 2.03 6.53 69.17 5.02 13 7 65 4.17 2.41 6.58 49.78 4.15 14 7 52 3.84 1.30 5.14 43.08 3.43 15 6 50 3 16 1.88 5.04 26.92 2.15 16 6 40 2.91 1.17 4.08 24.10 1.80 17 5 34 2.13 1.25 3.38 13.40 1.21 18 5 30 2.06 .88 2.94 12.50 1.09 19 4 28 2.15 .75 2.90 7.69 1.17 20 4 18.5 1.34 .56 1.90 5.14 .49 21 3 23 1.72 .53 2.25 3.29 .77 22 3 17 1.37 .34 1.71 2.66 .48 ELEMENTS OF PENCOYD BEAMS. 93 ELEMENTS OF PENCOYD BEAMS. IX. X. XI. XII. XIII. XIV- li SIZE IN INCHES. S CHART 1 ,_ -* NUMBER. RADII OF GYRATION. CO-EFFICIENT SAFE LOAD DISTRIBUTED. CO-EFFICIENT FOR DEFLECTION. Axis A. B. Axis C. D. Load in Centre. Load Dis- tributed. 5.86 1.20 424.41 . 0000041 .0000025 43.20 15 5.98 1.08 324.30 .0000053 .0000033 22.10 15 2 4.69 1.17 289.32 .0000074 .0000046 38.63 12 3 4.78 1.01 212.22 .0000101 .OCOOC63 22.22 12 4 4.24 1.19 214.78 .0000115 .0000072 22.13 101 5 4.25 1.07 173.71 .OOC0142 .0000089 17.71 101 6i 4.26 .97 144.23 .0000171 .0000107 13.35 104 6 3.94 .98 162.02 .0000159 .0000099 23.68 10 7 4.05 .95 138.43 .0000186 .0000116 13.18 10 8 3.62 .96 123.21 .0000232 .0000145 16.53 9 9 3.68 .89 97.94 .0000292 .0000183 9.94 9 10 3.21 .94 97.92 .0000329 .0000205 15.49 8 11 3.25 .88 80.70 .0000099 .0000249 10.46 8 12 2.75 .79 66.38 .0000546 .0000341 15.69 7 13 2.89 .82 57.44 .0000640 .0000400 6.17 7 14 2.31 .65 41.87 .0001025 .0000641 12.77 6 15 2.43 .66 37.49 .0001144 .0000715 6.50 6 16 1.99 .60 25.01 .0002059 .OC01C87 8.01 5 17 2.06 .60 23.33 .0002206 .0001379 4.86 5 18 1.63 .63 17.94 .0003589 .0002243 5.12 4 19 1.65 .51 12.00 .C005366 .0003354 3.03 4 20 1.21 .59 10.24 .0008382 .0005-239 4.11 3 21 1.25 .53 8.28 .0010366 .0006479 2.34 3 22 94: WROUGHT IKON AND STEEL. ELEMENTS OF FENCOYD CHANNELS. I. CHART NUM- BER. II. III. IV. V. VI. VII. VIII. SIZE IN INCHES. WEIO'T PER YARD. AREAS IN SQUARE INS. MOMENTS OP INERTIA Flanges Web. Total. Axis A. B. Axis C. D. 30 15 148 6.50 8.36 14.86 451.51 19.05 31 32 12 12 88.5 60 4.59 2.87 4.24 3.07 8.83 5.94 182.71 123.71 7.42 3.22 34 10 60 3 5(5 2.43 5.99 92.08 4.2D 35 10 49 2.67 2.22 4.89 73.91 2.33 36 9 54 2.97 2.43 5.40 64.34 2.47 37 9 37 1.81 1.91 3.72 43.65 1.31 38 8 43 2.28 1.97 4.25 40.00 2.17 39 8 30 1.34 1.62 2.96 28.23 1.06 40 7 41 2.30 1.80 4.10 29.51 1.71 41 7 26 1.38 1.26 2.64 18.46 .90 42 6 33 2.04 1.25 3.29 18.37 1.46 44 6 23 1.09 1.18 2.27 11.67 .59 45 5 27.3 1.69 1.04 2.73 10.29 .86 46 5 19 .91 .97 1.88 6.67 .37 47 4 21.5 1.34 .81 2.15 5.16 .54 48 4 17.5 1.02 .73 1.75 4.14 .41 49 3 15 .86 .66 1.52 2.03 .32 50 ft 11.3 .69 .44 1.13 .80 .21 51 2 8.75 .55 .33 .88 .48 .08 ELEMENTS OF PENCOYD CHANNELS. 95 ELEMENTS OF PENCOYD CHANNELS. IX. x XI. XII. XIII. XIV. XV. II. I. RADII OF GYRATION. Ill CO-EFFICIENTS FOR DEFLECTION. p 81? o M "si h 3 Axis Uxie W fc H 6-" 1 2 Load in Load dis- ||| tt og A. B. C. D. o*P centre. tributed. r i S 02 5.51 1.13 280.94 .0000061 .0000038 40.64 .95 15 30 4.55 .92 142.11 .0000151 .OOOC094 18.49 .71 12 31 4.56 .74 96.22 .0000223 .0000139 9.14 .62 12 32 3.92 .84 85.94 .0000298 .0000186 9.10 .75 1 10 34 3.89 .61) 68.98 .0000374 .0000234 7.25 .64 10 35 3.45 .68 66.73 .0000429 .0000268 ! 10.87 .67! 9 36 3.43 .59 45.27 .0000632 .0000395 6.38 .55 9 37 3.06 .71 46.66 .0000690 .0000431 8.77 .60 8 38 3.09 .60 32.94 .0000977 .0000611 4.79 .50 8 39 2.68 .65 39.35 .00009^5 .0000584 9.07 .65 7 40 2.64 .58 24.61 .0001495 .0000934 3.42 .48 7 41 2.36 .67 28.58 .0001501 .0000938 6.50 .66 6 42 1 2.27 .51 18.16 .0002363 .0001477 5.24 .46 6 44 1.93 .56 19.21 .0002680 .0001675 5.92 .61 5 45 1.88 .45 12.45 .0004136 .0002585 4.86 .42 5 46 1.55 .50 12.03 .0005349 .0003343 5.12 .53 4 47 1.54 .48 9.65 .0006667 .0004167 4.29 .45 4 48 1.16 .46 6.32 .0013584 .0008490 3.49 .51 3 49 .85 .43 3.33 .0034350 .0021470 3.20 .46 Si 50 .74 .3! 5 .0057230 .0035770 2.49 .37 2 51 96 WROUGHT IRON AND STEEL. ELEMENTS OP PENOOYD DECK BEAMS. - c - VJ ~ P -- J^-JB r I. II. III. IV. V. VI. VII. VIII. CHART SIZE WEIO'T AREAS m SQUARE INS. MOMENTS OF INERTIA NUM- IN PER 1 BER. INCHES. YARD. 1 Fl'ge 1 Bulb. Web. Total. Axis A. B. Axis C. D. 60 12 104 3.59 2.89 3.90 10.38 221.98 9.33 61 11 91 3.26 2.52 3.28 9.06 164.09 7.64 62 10 80 2.87 2.19 2.96 8.02 118.22 6.13 63 9 72 2.50 2.06 2.61 7.17 84.77 4.92 64 8 61 2.17 1.85 2.09 6.11 57.66 3.63 65 7 52 1.86 1.55 1.80 5.2-1 34.40 2.59 66 6 42 1.52 1.28 1.38 4.18 21.95 1.64 67 5 34 1.22 1.04 1.11 3.37 12.04 .98 ELEMENTS OF PENCOYD DECK BEAMS. 97 ELEMENTS OF FENCOYD DECK BEAMS. =OP_ IX. RAD GYRA Axis A. B. X. [I OF TION. Axis C. D. .95 XI. XII. XIII. XIV. XV. SIZE IN INCHES. S I. CO-EFFICIENT SAFE LOAD DISTRIBUTED. CO-EFFICIENTS FOB DEFLECTION. MAXIMUM LOAD IN TONS. DISTANCE, d, FROM BASE TO NEUTRAL Axis. M S| 60 Load in centre. Load dis- tributed. 4.62 172.6 .0000122 .0000078 18.50 5.24 12 4.25 .92 139.5 .0000168 .0000105 15.72 4.68 11 61 3.84 .87 110.3! .0000233 .0000146 15.26 4.27 10 62 3.44 .83 87.9 .0000325 .0000203 14.63 4.00 9 ! 63 3.07 .77 67.3 .0000478 .0000299 12.12 3.50 8 64 2.57 .71 45.8 .0000802 .0000501 11.30 3.20 7 65 2.29 .63 34.2 .0001257 .0000785 9.03 2.65 6 66 1.89 .54 22.4 .0002291 .0001432 8.01 2.22 5 67 WROUGHT IRON AND STEEL. ELEMENTS OF PENOO YD ANGLES. EVEN LEGS. I. II. III. IV. V. VI. VII. VIII. ~1~ ca MOMENTS OF RADII OF ss 1 S INERTIA. GYRATION. g'i^ 1 SIZE IN INCHES. || Axis Axis Axis Axis ill 4 ^ A. B. C.D. A. B. C.D. 120 6 x 6 x f e 50.6 17.68 7.16 1.87 1.19 1.66 6x6x1 110.0 35.46 15.00 1.80 1.17 1.86 121 5 x 5 x -j 3 ^ 41.8 10.02 4.16 1.55 l.OOj 1.41 5x5x1 90.0 19.64 8.67 1.48 .98 1.61 122 4 x 4 x 3- 28.6 4.36 1.86 1.24 .81 1.14 4 x 4 x | 54.4 7.67 3.45 1.19 .80 1.27 123 3i x 3i x 24.8 2.87 1.20 1.07 .70 1.01 3| x 3* x fc 39.8 4.33 1.85 1.04 .69 1.10 124 3 x 3 x i 14.4 1.24 .51 .93 .60! .84 3 x 3 x f 33.6 2.62 1.15 .88 .59 .98 125 2f x 2f x i 13.1 .95 .39 .85 .78 2| x 2| x i 25.0 1.67 .72 .82 !54 .87 126 2 x 24- x i 11.9 .70 .29 .77 .50 .72 2| x 2* x i 22.5 1.23 .54 .74 .49 .81 127 2^ x 2^ x i 2i x 2i- x -ft 10.6 17.8 .50 .79 .21 .34 .69 .67 .45 .44 .65 .72 128 2 x 2 x -fV 7 1 .27 .11 .62 .40 .57 2 x 2 x $ 13.6 .50 .21 .61 .39 .64 129 1| x 1J x A 6.2 .18 .08 .53 .36 .51 1| x 1| x i 11.7 .31 .14 .51 .35 .57 130 $4 X 1-f X 1% 5.3 .11 .05 .46 .31 .44 14 X 1 X 9.8 .19 .09 .44 .31 .51 131 H x 1\ x i 3.0 .05 .02 .41 .26 .36 H x li x i 5.6 .08 .04 .38 .26 .40 132 1 X 1 X i 2.3 .02 .01 .29 .20 .30 1 x 1 x i 4.4 .04 .02 .29 .20 .35 1 ELEMENTS OP PENCOYD ANGLES. 99 \ ELEMENTS OF \ A _ F -. PENCOYD ANGLES. UNEVEN LEGS. I. II. ni. IV. V. VI. VII. VIII. IX. X. XI. K w li MOM. OF INERTIA. RADII OF GYRATION. DlST. FROM BASE TO .NEUT.AXES s SIZE IN INCHES. p Axis Axis Axis Axis Axis Axis d. 3 A.B. C. D. E. F- A. B. C. D. E. F. O 140 6 x4 x-f fi 41.8 15.46 5.60 3.55 1.92 1.16 .92 1.96 .96 6 x 4 x 1 90.0 30.75 10.75 7.46 1.85 1.09 .91 2.17 1.17 141 5x4x| 32.3 8.14 4.66 2.47 1.59 1.20 .87 1.53 1.03 5x4x1 80.0 18.17 10.17 6.10 1.51 1.18 .86 1.75 1.25 142 5 x 3 x a. 30.5 7.78 3.23 1.95 1.60 1(3 .80 .61 .86 5 x 3^ x 58.1 13.92 5.55 3.72 1 55 '.98 .79 .75 1.00 143 5 x 3" x $ 28.6 7.37 2.04 1.42 1.61 .85 .70 .70 .70 5 x 3 x | 54.4 13.15 3.51 2.58 1.55 .80 .69 .84 .84 144 4* x 3 x i 86.7 5.50 1.98 1.27 1.44 .86 .69 .49 .74 4^ x 3 x t 43.0 8.44 2.98 2.04 1.40 .83 .68 1.58 .83 145 4 x 3J- x f 26.7 4.17 2.99 1.44 1.25 1.06 .74 1.20 .95 4 x:sf x f 43.0 6.37 4.52 2.34 1.22 1.03 .73 1.29 1.04 146 4 x 3 x f 24.8 3.96 1.92 1.10 1.26 .88 .67 1.28 .78 4x3x1- 89 8 6.03 2.87 1.69 1.23 .85 .65 1.37 .87- 147 3 x 3 x J 81.2 2.53 1.72 .86 1.09 .90 .64 1.07 .82 3i x 3 x 36.7 4.11 2.81 1.49 1.06 .87 .64 1.17 .92 148 3 x 2fc x ft 16.2 1.42 .90 .47 .94 .74 .54 .93 .68 3 x 2i x i 25.0 2.08 1.30 .72 .91 .72 .54 1.00 .75 149 ,3 x 2 x i 11.9 1.09 .39 .25 .96 .68 .4(5 .9 .49 |3 x 2 x i 22.5 1.92 .67 .47 .92 .55 .46 1*08 .58 150 j3 x 2 x -fa 17.8 2.19 .94 .56 1.11 .73 .56 1.14 .64 [8| x 2j x 27.5 3.24 1.86 .87 1.08 .70 .56 1.20 .70 151 6 x 3i x & 39.6 14.76 3.81 2.68 1.93 .98 .82 2.06 .81 6 x 8i x 1 85.0 29.24 7.21 5.75 1.86 .92 .81 2.26 1.01 152 16^x4 xft 6 x 4 x 1 44.0 95.0 19.29 38.66 5.723.87 11.008.35 2.(i9 2.02 1.14 1.08 .94 .93 2.18 2.88 .93 1.18 153 5Jr X 3 X f 32.3 10.12 3.2712.14 1.77 1.05 .81 1.82 .82 5| x 3| x | 52.3 15.73 4.963.35 1.73 .97 .80 1.91 .91 154 7 x 3| x | 01.7 30.25 5.284.45 2.21 .92 .85 2.57 .82 7 x 3 x l||95.0 |45.37 7.536.70 2.19 .88 .84 2.71 .96 155 2 x 2 x i 110 6 .71 .37 .20 .81 .59 .43 .78 .54 2^ x 2 x | 20.0 1.09 .63 .3? .74 .56 .43 .87 .62 156 2i x H x 1 3 6 6 7 .34 .13 .08 .71 .43 .34 .76 .38 8i x li x 2 12.6 .5( .21 .15 .63 .40 .34 .82 .44 157 2 x 1* x A 5.7 .23 .07 .05 .63 .35 .31 .68 .31 2 x H x f 9.2 o. .10 .08 .59 .33 .29 .70 .32 100 WROUGHT IKON AND STEEL. C ELEMENTS OF A x-B PENCOYD TEES. EVEN LEGS. I. II. III. IV. V. VI. VII. VIII. fc H O 70 SIZE IN INCHES. WEIGHT PER YARD. MOMENTS OF INERTIA. KADII OF GYRATION. DISTANCE, Qfi ftfi Radius of gyration of the latter y ^- go =4.60 inches. The radius of gyration will be found to alter very little, and for all practical purposes, the tabular figures may be accepted within the range of section possible for each shape. The above is only a close approximation for deck beams. FOR ANY I BEAM OR DECK BEAM. AXIS PARALLEL WITH WEB. The following rule gives a close approximation for the mo- ment of inertia. Multiply the increase of area in square inches by the total thickness of web in the enlarged section. This product added to the tabular number in col. 8, will give the moment of inertia for the enlarged section. Example. A 10" I Beam, No. 8, area 9 square inches is in- creased to 10f square inches, having a web thickness of .525 inches. . 525 x l = . 7875, which added to the amount in col. VIII., 8.09 + .78 = 8.87, the moment of inertia required. Radius of gyration of least section = A/ _ = . 95 inches. f 9 Radius of gyration of enlarged section = 4/ =.92 inches. ' 10.5 The radius of gyration alters but very little, and may be ac- cepted as practically unchanged within the limits that any shape can be increased. CHANNELS. For channels, in relation to axis parallel to web the moment of inertia increases nearly in a direct ratio to the increase of sectional area, but not precisely so, this ratio being too great for the larger sections and too little for the smaller sizes of channel bars. The radius of gyration alters but little as the sectional area is 108 WKOUGHT IKON AND STEEL. changed, and practically may be accepted as unchanged within the range of variation possible for any particular size. The distance d will not vary sufficiently in any section be- tween the limits of minimum and maximum to make any prac- tical difference in ordinary calculations where it may be used. ANGLES. For angles referring to any axis passing through the centre of gravity, the inertia increases nearly in the same ratio as the area increases. Our table gives values of / for the minimum and maximum sections ; any intermediate section can be obtained by proportion unless great accuracy is required. Our tables ex- hibit the change in values of R between the least and greatest sections, which in the case of small angles remain practically unaltered within the range of possible variation of area. INERTIA OF COMPOUND SHAPES. " The moment of inertia of any section about any axis is equal to the /about a parallel axis passing through its centre of grav- ity + the area of the section multiplied by the square of the distance between the axes." By use of this rule the moments of inertia or radii of gyration of any single sections being known, corresponding values can readily be obtained for any combination of these sections. TV^js i i.i-\-T msia Example No. 1. A combination of two 9" 54 Ib. Channels, and two 12 x { plates as shown. fc ;/ I >H AXIS A B OF SECTION. /for B 2 channels, col. VII, page 94, = 128.680 / for 2 plates = i?_^ i?2! x 2 = . 03125 ) r 6 (area of plates) x 4f a = 128 . 34375 ) = 128 . 375 /for combined section = 257.055 which divided by area (14) gives 18.3611 - R 2 or 4.285 radius of combined section. MOMENTS OF INERTIA. 109 AXIS C D. Find distance d = (.67) from col. XV., page 95, then obtaining the distance (4.2325) between axes CD and EF. /for 2 channels around axis JZFfrom col. VIII., = 4.94 Area of channels x square of distance = 10.8 x 4.2325' = 193.471 / for 2 plates =' 5 * 123 = 72. / for combined section 270 . 41 1 Radius of gyration = j/ 270 ' 411 =4.395. By similar methods, inertia or radius of gyration for any com- bination of shapes can readily be obtained. Example No. 2. A " built-up beam " composed of : ~~ >!l " 4 angles 3" x 3" x \". 2 plates 8" x |". 1 plate 15" x F. AXIS A B. /of two 8" x | plates = 9 * ^ x 2 = .167 + 8 (area) x 7f (sq. of distance d) =480.5 480.667 /of one 15" x |" plate = ^^= 105.469 /of four 3 x 3 x i angles = 4 x 1 .24 (see col. \ IV, page 98), = 4.96 } + 5.7" (area) x 6.66 2 (sq. of distance d 1 ) =255.045* 260.005 Inertia of combined section around A B = 846 . 141 846.141 _ ,. .. 7846.141 Radius of gyration =|/ -jg-g-^ = 6 - 61 - 110 WROUGHT IRON AND STEEL. AXIS C. D. lot two 8 x \ plates =^jj^ x 2 = 42.667 I of one 15 x | plate = ^^- = .066 La lot four 3 x 3 x angles = 4 x 1.24 (see col. IV, page 98) + 5 . 75 (area) x 1 . 0275 2 (sq. of distance d") - 11.031 ee \ = 4.96 t d" = 6 . 071 ) Inertia of combined section around C D = 53 . 764 Radius of gyration = V 53 - 764 = 1 . 66. ' 19 . 375 RADIUS OF GYRATION OF COMPOUND SHAPES. In the case of a pair of any shape without a web the value of It can always be readily found without considering the moment of inertia. The radius of gyration for any section around an axis parallel to another axis passing through its centre of gravity, is found as follows : Let r = radius of gyration around axis through centre of grav- ity. R radius of gyration around another axis parallel to above, d distance between axes. "When r is small, R may be taken as equal to d without mate- rial error. Thus in the case of a pair of channels latticed to- gether, or a similar construction. Example No. 1. Two 9" 54 Ib. channels placed 4.66" apart, E E required the radius of gyration around axis CD l-j ^ for combined section. Find r on col. X., page 95, = .68 and r 2 = .4624. Find distance from base of channel to neutral axis col. XV., same page, = .07, this added to \ distance between the two bars, 2.33"= 3" = d, and d* 9. Radius of gyration of the pair as placed equals, MOMENTS OF INEETIA. Ill The value of J? for the whole section in relation to the axis A B is the same as for the single channel, to be found in the tables. Example No 2. Four 3" x 3" x f" angles placed as shown; form a column 10 inches square; required the i 8 y,radius of gyration. Find T OQ C0i> VI) P age 98 ' = - 91 ' atld ? ' 2 ~ -8281. Find distance from side of angle to neutral P| f\ axis, coi. VII. , same page, = . 89. Subtract this I i _ t j | from | the width of column =5. .89 = p 4.11 = d or distance between two axes, d 2 = 16.8921. Radius of gyration of 4 angles as placed = -i*" 3 ""! I?* s _ i 8 I'M IJi 11 _ -Y/16.8921 + .8281 =4.21. When the angles are large as compared with the outer dimen- sions of the combined section, the radius of gyration can be taken without serious error from the table of radii of gyration for square columns, on page 155. 112 WROUGHT IRON AND STEEL. O O Q sil i fc ^ M * * "*^ -i h ill o g r S - g| g ^S 5 |* s a |* j 1 ""v ' ^aS s ^ II RATION. h-H CC ^ O H * * ^J ^ ^ * * fc A^ '_|j _ o % *b e. htaJ ^ ^* * 9 p rh >-> P ^o.S O O <33 5 H t3 + iH S + ^ ^ ' S c* ^ ^o ^ P^ ill! IB S fo e g e? S S ^nS'.S ^ ^ ^ S J^'s 3 p 1 ^ p ^5.2^ o"s i 1 P" 8 S3 8 g ri 'S O >-, i ill PI ill i ^ ""o i * * S o ^5 ^ A o $ g o| 8 ^ |s 5 M t-i "P 1 g S.2 11 M 8|i h 9 ^ea o B22 w O o a ii ii w B i i (2 - J I s t" ^ p ^ lit i in n S O O RADIUS OF GYRATION. 113 ! 1 1 1 j 1 c 1 V3 X ^ J ^ ^ 5 1 ! 1 W ^H P gj 01 'd T3 | "O O i i c be "8 a ? -^ a Ifi > ' O CO -i- 3 C GQ *g 04 c3 , E a | I T-l t^ I * M 9 c TH g ^ 1 d s ^ 1 00 s hJ f i S J 3 w p-l J| 0 70 34,000 34,000 33,750 27,750 80 32,000 3-2,000 31,500 25,000 90 30,900 31.000 29,750 22,750 100 29,800 30,000 28,000 20.500 110 23,050 29,000 26,150 18,500 120 26,300 28,000 24.300 16500 130 24.900 26,750 22,650 14.G50 140 23,500 25,500 21,000 12,800 150 21,750 24,250 18,750 11,150 160 20,000 23,000 16,500 9,5 170 18,4: K) 21,500 14,650 8,500 180 16,800 20,000 12,800 7,500 190 15.650 18,750 11,800 6.750 200 14.500 17,500 10.800 6,000 210 13,600 16.250 9.800 5,500 220 12,700 15,000 8.800 s.noo 230 11,950 14,000 8.150 4,650 240 11,200 13,000 7.500 4,300 250 10,500 12,000 7,000 4,050 260 9,800 11,000 6,500 3,800 270 9,150 10,500 6.100 3.500 280 8,500 10,000 5,700 3,200 290 7,850 9,500 5.350 3,01)0 300 7,200 9000 5.000 2.800 310 6,600 8,500 4,750 2.650 320 6,000 8.000 4,500 2,500 330 5,550 7,500 4,2.50 2,300 340 5,100 7,000 4,000 2.100 350 4,700 6,750 3.750 2,000 360 4,300 6,500 3500 1,900 370 3.900 6.150 3.250 1,800 380 3.500 5.800 3,000 1,700 390 3,250 6,800 2,750 1,600 400 3,000 5,200 2.500 1,500 410 2750 5,0(10 2,400 1,400 420 2.500 4.800 2.300 1,300 430 2,.350 4.550 2.200 440 2,200 4.300 2,100 450 2,100 4,050 2,000 460 2,000 3,8CO 1,900 470 1,950 1,850 480 1,900 1,800 WROUGHT IRON STEUTS. 119 No. 2. GREATEST SAFE LOADS ON STRUTS. Greatest safe load in Ibs. per square inch of cross section *or vertical struts. Both ends are supposed to be secured as indicated at the head of each col- umi?.. If both ends are not secured alike, take a mean proportional between the values given for the classes to which each end belongs. If the strut is hinged by any uncertain method so that the centres of pins and axis of strut may not coincide, or the pins may be relatively small and loosely fitted, it is best in such cases to consider the strut as " round ended." LENGTH FLAT FIXED HINGED ROUND LEAST RADIUS OP GYRATION. ENDS. ENDS. ENDS. ENDS. 20 30 14,380 13,030 14.380 13,' 30 13,940 12,460 13,330 11,670 40 11,760 11,760 11.110 10.140 50 10,860 10,860 10,130 8,930 60 10,000 10,000 9,230 7,820 70 9,190 9.190 8,330 6,850 80 8,420 8,420 7,500 5,950 90 7,920 7,950 6,840 5,230 100 7,450 7,500 6,220 4,560 110 6,840 7.070 5.620 3,980 . 120 6,260 6,670 5.060 3,440 130 5, '.90 6,220 4.580 2,960 140 5,340 5,800 4,120 2,510 150 4,830 5,390 3.570 2,120 160 4,350 5,000 3,060 1,760 170 3,920 4,570 2,640 1,530 180 3,500 4.170 2,250 1,310 190 3,190 3,830 2,020 1,150 200 2,900 3,500 1,800 1,000 210 2,<;70 3,190 1,590 890 220 2,440 2.880 1,400 790 230 2,250 2.G40 1,260 720 240 2,070 2,410 1,140 650 250 ,910 2,180 1,040 600 260 ,750 1.960 940 550 270 ,610 1,S40 870 500 280 ,460 1,720 790 440 290 ,330 1,610 730 410 300 1,200 1,500 670 370 310 ,080 1,390 620 350 320 970 1,290 580 320 830 880 1,190 540 290 340 800 IJ'90 490 260 350 720 1,040 450 240 360 650 980 420 230 370 580 920 380 210 380 510 850 340 200 890 470 800 310 80 400 430 740 280 70 120 WKOUGHT IRON AND STEEL. ROLLED STRUCTURAL SHAPES AS STRUTS. The following tables for the working values of various rolled structural shapes as struts are derived directly from Table No. 2. The radii of gyration are taken from Tables of Elements, pages 92-101. In all cases the strut is supposed to stand verti- cal. In short struts this distinction is immaterial, but when the length becomes considerable, the deflection resulting from its own weight, if horizontal, would seriously affect the stability of the strut. The tables are calculated for the minimum section of each shape. For sections increased above the minimum the resist- ance per square inch will dimmish. This amount can be accu- rately determined by finding the correct radius of gyration for the enlarged section as heretofore described. But within the range of variation of section possible for any shape, the tables may be accepted as practically correct. The head notes to the- tables indicate the condition assumed for each class of Ft ruts. If the pins should be placed otherwise than as described in the tables, the strut may be either weaker or stronger, according to circumstances, which have to be determined for any particular case. This results from the fact that a pin-connected strut if properly designed should be considered hinged ended, only in the direction in which it is free to rotate on the pin. 'In the direction of the axis of the pin it can be treat ed as a " flat ended " strut. An I beam strut of the character described in Tables 3, 4, and 5, braced laterally in the direction of its flanges should be considered also by Tables 6, 7, and 8, as a series of short struts whose lengths, are the distances between points of bracing, and liable to fail in the direction of the flanges. Example. An 8" 65 Ib. I beam, 18 feet long is used as a strut having pins at both ends at right angles to web. It would then be flat ended in the direction of the- flanges, and by Table No. 7 the greatest safe load 1,990 Ibs. per square inch of section. If braced in the direction of the flanges at two points 6 feet apart it should then be considered as a series of flat ended struts C feet long, whose safe load by Table No. 7, would be 8,320 Ibs. per square inch. CHANNEL STRUTS. 121 In the direction of its web it remains a hinged-ended strut 18 feet long, and safe load by Table No. 4 8,690 Ibs. per square inch. CHANNEL STRUTS. The foregoing remarks apply also to channels, which are seldom used individually as struts, but frequently in pairs. When so used, if the methods of connection are not of such a nature as to insure the unity of action of the pair, they should be treated as an assemblage of separate struts . But if connected by a proper system of triangular latticing, the pair can be considered as a unit, and each channel treated as a series of short struts whose length is the distance between centres of latticing. Example. A pair of 9" 54 Ib. channels, separated, etc., as described on page 110, are connected by triangular latticing, forming a hinged-ended strut 10 feet between pin centres. WLat is the greatest safe load, and how far can latticing be spaced ? As described on page 95, radius of gyration around axis across the web of channel, or in the direction of the pin = 3 . 45 inches. Eadius of gyration in opposite direction = 3.07 inches. Least radius of gyration for a single channel = . 68 inch. for hinged-ended direction = 35, and by Table No. 2 Safe Load =11, 800 Ibs. for flat-ended direction = 39, and by same T table greatest safe load = 11,900 Ibs. For each single channel the greatest length between latticing = radius of gyration x 39 = 26| inches. It is customary and is also good practice to reduce the dis- tance between lattice centres below v'liat the above calculation would require. Tables Nos. 12-14, give the greatest safe loads per square inch of sectional areas, for struts composed of a pair of channels properly connected together, so as to insure unity of action. The figures are derived from Table No . 2. The distances D or d, for channels placed flanges inward or flanges outward respectively, make the radii of gyration equal lor either direction of axis. These distances should not be diminished, and may be ad van- 122 WROUGHT IRON AND STEEL. tageously increased, especially for hihged-ended struts, if the pin is placed parallel to the webs of the channels. These tables are calculated for the standard minimum section of each channel. The distance d may be slightly diminished for sections heavier than the minimum, but the diminution can be so little that it is practically unnecessary to notice it. Under each length of struts in the table I represents the greatest distance apart in feet that centres of lateral bracing can be spaced, without allowing weak- ness in the individual channels. The distance I is obtained as shown in last example, that is, by making = T Mi I = length between bracing. L = total length of strut. T = least radius of gyration for a single channel. JB = least radius of gyration for the whole section. STEEL STKUTS. 123 STEEL STRUTS. A table for the ultimate resistance of flat-ended struts of two grades of steel will be found on page 31. These grades prob- ably embrace the extremes of the material, that is, the hardest and softest steels that are likely to be used in struts. Experiments on this material are not sufficiently complete to warrant a full statement of resistances of the various grades, and for the various conditions of the strut, such as the methods of connecting the ends, etc. It is probable, however, that the relations existing between the four classes of wrought-iron struts, as given in the following tables, will also prevail in the same ratios for steel. The safe loads for steel struts of any section or length, can therefore be obtained by increasing the figures in the following tables, for any ratio of , in the proportions given on page 81, as existing T between flat-ended struts of iron and steel. When a grade of steel is used, intermediate in hardness be- tween the mild and hard heretofore described, it is probable that the strut resistance for such material may be safely approxi- mated by simple proportion. For instance, the steels referred to had carbon ratios of . 12 and .38 per cent, respectively. A mean proportion of these would be .24 per cent. It is probable that steel of latter grade would possess inter- mediate compressive resistance between the two grades described from our experiments. 124: WROUGHT IKON AND STEEL. No. 3. PENCOYD I BEAMS AS STRUTS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION. When the struts are secure from failure in the direction of the flanges, and can bend only in the direction of the web C D. Using factors of safety given in previous tables. SIZE CONDITION LENGTH IN FEET. BEAM. OP 8 10 12 14 16 18 20 22 24 IK" Fixed Ends.. . 14240 13700 13160 1-2650 12140 11670 11310 10950 L U Flat Ends 14240 13700 13160 12650 12140 11670!! 1310 10950 Heavy Hinged Ends... 13790 1 13200! 12610! 12050 11510 11010,10620 10230 I i = 5 Htt Round Ends 13160 12500 11840 11210 10600 10020 9530 9050 ;, Fixed Ends 14380 13840 13300 1278:) 12270 11760 11400 11040 -L t/ Flat Ends 14380 1384 l 13300 12780 12270 11760 11403 11040 Light 6 _. Hinged Ends... 13940 13350 12760 1 '21 90 1 1650 1111010720 10330 Round Ends. 13*30 12670 12000 11360 10750 101401 9660 9170 1 9" Fixed Ends | 14380J13570 12900 12270 11670 11220 10770 10340 9920 L _j Heavy Flat Ends Hinged Ends... 1438013570 13940 i 13050 12900 12270 11670 11220 10770 10:340 123201 1 1 650 ! 1 1010 10520 10040 9590 9920 9140 r = 4-69 Round Ends 13330 12330 11520 10750 10020 9410 8820 8260 7720 1 9" Fixed Ends.... 14380 13700 13030 12400 11760 11310' 10860 10430 10000 JL Flat Ends 14880 13700 13030 12400, 11760 11310 108<>0 10430 10000 Light , HiMgedEnds... 13940 13200 12460111780 11110 106-20 10130 9680 9230 I 4-7S Round Ends 13330 12500 116rt) 10900 10140 9530 8930 8370 7820 -mi" Fixed Ends. . 13970 13160 12400 11760 11220 10690 10170 9760 9270 -L U n" Plat Ends 139 ;0 1316012400 11760 1 1220 10690J 10170 9760 9270 Heavy.... Hinged Ends. . . 13500 1261011780 11110 10520 9950 9410 8960 8420 r = 434 Round Ends 12830 11840 10900 10140 9410 8710 8040 7530 6950 ioy Fixed Ends... Flat Ends 13970 13970 13160 13160 12400 12400 11760 1 1760 11220(10690 1122010690 10170' 9760 10170 9760 9270 9270 Light .... Hinged Ends. . . 13500 12610 117801111010530 9950 9410 8960 8420 r = 4-2 Round Ends 12830 11840 109001 10140 9410 8710 8040, 7530 6950 1 0" Fixed Ends... 13840 13030 1214011490 10950 10430 99L'0 9430 8960 Flat Ends Heavy 1 Hinged Ends. . . 1384013080 1335012460 12 140 11 490 10950! 10430 1151010820102301 9680 9920 9430 9140 8600 8960 r-s-94 [Round Ends.... 1267011670 10600 9780 9050 8370 7720 ; 7140 6580 TABLE OF STRUTS. 125 No. 3. PENCOYD I BEAMS AS STRUTS. |A -C-- --D. In the marginal columns r indicates the radius of gyration taken around axis A B. When strut is hinged the pins are supposed to lie in the direc- tion A B. Under the conditions stated the strut may be considered flat ended in direction A B. LENGTH IN FEET. CONDITION OF SIZE OF 26 28 30 32 34 36 38 40 42 ENDS. BEAM. 10600 10260 9920 9510 9190 8880 8580 8330 8140 Fixed Ends... 1 K" 10600 1 02(50 9920 9510 9190 8880 8580 8320 8120 Flat Ends 10 9860 8600 9.500 815U 9140 772U 8690 7240 8330 6S50 8000 6490 7670 6130 7370 5810 7100 5420 Hinged Ends... Round Ends Heavy. r== 6-86 10690 10340 10000 9680 9350 9040 8730 S420 8230 Fixed Ends... 1 " 10690 10340 10000 8680 9350 9040 8730 8420 8220 Flat Ends 10 9950 9590 9230 8870! 8510 8160 7830 7500; 7240 Hinged Ends. . . Light. 8710 8260 7820 743C 7040 6670 6310 5950 5660 Round Ends r -= 8-88 9430 9040 8650 8330, 8090 7860 7630 7410 7190 Fixed Ends... 19" 9430 9040 8650 8320 1 8070 7830 i 7590 7330 7020 Flat Ends L4 8600 7140 8160 6670 7750 6220 73" 5810 704U 5350 6720 5100 6410 4760 6100 4440 5800 4150 Hinged Ends... Round Ends Heavy. r = 4-69 9590 9190 8800 8420 8180 7950 7720 7500 7280 Fixed Ends 19" 9590 9190 8800 8420 8170 7920 7680 7450; 7140 Flat Ends... 1 ~j 8780 8830 7910 7500 7170 6840 ; 6530 6220! 5920 Hinged Ends. . . Light. 7330 6850 6400 5950 5490 5230 4890 4560 4270 Round Ends I =4-78 8800 8420 8140 7860 7590 7320 7070 6S70 6620 Fixed Ends... 1 ft 1 " 8800 8420 8120 7830 7540 7210 6840 6550 6210 Flat Ends i-'Vj 7910 7500 7100 6720 6340 5980 5620 5340 5010 Hinged Ends... Heavy. 6400 5950 5420 5100 4690 4320 3980 3710 3390 Round Ends r = 4-34 8800 8420 8090 7810 7540 7320 7070 6870 6620 Fixed Ends ,, 8800 8420 8070 7780 7500 7210! 6840 6550 6210 Flat Ends J Uf 7910 7500 7040 6650 6280 980 5620 5340 5010 Hinged Ends... Light. 6400 5950 5350 5030 4630 4320 3980 3710 3390 Round Ends... . r = 4-26 8500 8180 7900 7630 7320 7070 6830 6580 6310 Fixed Fnds 1 fj" 8500 8170 7870 7590 7210 6840 6490J 6160 5880 Flat Ends 1 U 7580 7170 6780 64101 5980 5620 5280 4960 4670 Hingc-d Ends... Heavy. 6040 5490 5160 4760J 4320 3980 3650 3340 3050 Round Ends. . . . r 3-94 126 WROUGHT IRON AND STEEL. No. 4. PENCOYD I BEAMS AS STRUTS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION. When the struts are secure from failure in the direction of the flanges and can bend only in the direction of the web C D. Using factors of safety given in previous tables. SIZE CONDITION LENGTH IN FEET. OF BEAM. OP ENDS. 6 8 10 12 14 16 18 20 22 1 0" Fixed Ends 13840 13030 12270 11670 11130 10600 10090 9590 1U Light . . . Flat Ends 13840 13350 13030 12270; 116701 11 130 10600 12460I11650H101010420 9860 10090 9320 9590 8780 Hinged Ends r 4-05 Round Ends. 12670 11670 10750 10020 9290 8600 7930 7330 Q" Fixed Ends 14380 13430 12650 11760 11130 10600 10000 9510 8960 V Flat Ends. ... 14380 13430 12650 11 760! 11 130 10600 10000 9510 8960 Heavy. . . . Hinged Ends. .. 13940 12900 12( 50 11110 10420 9860 9230 86fO 8080 r = 3-62 Round Ends 13330 12170 1121010140 9290 8600 7820 7240 6580 Q" Fixed Ends.... 14380 13570 1265011890 11220 10690 10090 9590 9040 C7 Flat Ends 14:380 13570 1-2650,1189011220 10690 1(1090 ! 9590 9040 Light .... r = 3-66 Hinged Ends... Round Ends 13940 13330 13050 12330 12050 11210 11240 10290 10520 9410 9950 8710 9320 7930 8780 7330 8160 6670 Q" Fixed Ends... 14110 13030 12140 11310 10690 lOfOO 9430 8800 8330 o Flat Ends 14110 130301 121401 11310 10690 10000 9430: 8800 8320 Heavy Hinged Ends... 13640 12460 11510 10620 9950 9230 86001 7910 7370 r =3-21 Round Ends 13000 11670 10600 9530 8710 7820 7140 6400 5810 Q" Fixed Ends 14110 13160 12140 11400 10690 10090 9510 8880 8370 o Flat Ends 14110 13160 12140 11400 10690 10(90 1510 88K) 8370 Light .... Hinged Ends... 13640 1261011510 10720 9950 9350 8690 8000 7430 r^ 3. us Round Ends 13000 11840 10600 9660 8710 7930 7240 6490 5880 7" Fixed Ends 13570 12400 11400 10690 9920 9190 8500 8090 7380 I Flat Ends 113570 12400 11400i 10690 9920 9190 8500, 8070 7640 Heavy Hinged Ends. .. Round Ends 13050 12330 11780 10900 10720 9660 9950 8710 9140 7720 8380 6850 7580 6040 7040 5350 6470 4830 7" Fixed Ends 13700 12650 11580 10860 10170 9510 8800 8280 7900 I Flat Ends 137001265011580 1086010170 95101 8800 8270 7870 Wtw Hinged Ends. .. Round Ends 1S2WO 12050 10910 1250011210 9900 10130) 9410 8690] 7910 7300 8930 8040 7240 6400J 5730 6780 5160 TABLE OF STRUTS. 127 No. 4. PENCOYD I BEAMS AS STRUTS. U -c- |B In the marginal columns r indicates the radius of gyration taken around axis A B. When strut is hinged the pins are supposed to lie in the direc- tion A B. Under the conditions stated the strut may be considered flat ended iu direction A B. LENGTH IN FEET. CONDITION SIZE 24 26 28 30 32 34 36 38 40 OF ENDS. OF BEAM. 9110 81550 8280 8000 7720 7450 7190 6990 6750 Fixed Ends... 10" 9110 8650 8270 7970 7680 7390 7020 6720 6370 Flat Ends 1 \J 8250 7750 7300 6910 6530 6160 5800 5500 5170 Hinged Ends... Light. 6760 6220 5730 5200 4890 4500 4150 3870 3540 Round Ends . . . r =4-05 8420 8140 7810 7540 7240 69,50 6710 6400 6090 Fixed Ends... 0" 84-20 8120 7780 7500 7080 6660 6310 5970 5650 Flat Ends V 7500 7100 6650 6280! 5860 5450 5110 4770 4440 Hinged Ends.. Heavy. 5950 5420 5030 4630 4210 3810 3490 3150 2820 Round Ends i = s-ea 8580 8180 7900 7590 7320 7030 6790 6490 6170 Fixed Ends... Q" 8580 8170 7870! 7540 7210 6780 6430 6070 5740 Flat Ends... t7 7670 7170 6780! 6340 5980! 5560 5220 4860 4530 Hinged Ends... Light. 6130 5490 5160 4690 4320 3920 3600 3240 2910 Round Ends.... r 3-63 7950 7630 7280 6990 6670 6350 6010 5710 5430 Fixed Ends... 0" 7920 75:iO 7140 6?20 6260 5930 5560 5230 4880 Flat Ends... o 6840 6410 5920 5500 5030 47'20 4350 4010 3620 Hinged Ends... Heavy. 5230 4760 4270 3870 3440 3100 2730 2430 2150 Round Ends r =" 3-21 8000 7680 7320 7030 6750 6400 6090 5500 5510 Fixed Ends... Q" 7970 7640 7210' 6730 6370 5970 5650 5340 4<)80Flat Ends O 6910 64701 5980 5560 5170 4770 4440 4120 3730 Hinged Ends... Light. 5200 4830 4320 3921) 3540 3150 2820 2510 2230 1 Round Ends.... r =3-25 7280 6950 6580 6110 5800 5470 5110 4740 4370: Fixed Ends... hn 7110 6660 6160 5740' 5340: 4930 4490 4090 3710 Flat Ends ( 5920 54,50 4960 4530 4120! 3680 3210 2800 2440 Hi used Ends... Heavy. 4270 3810 3340 2910 2510 2190 1860 1620 1420 Round Ends I = 2-75 7500 7150 6830 6440 6090 5750 5430 5070 4740 Fixed Ends . . . H" 7450 (5960 6490 6020 5650 5280 48SO 4440 4090: Flat, Ends I 6220 4560 5740 4090 5280 4820 ! 4440 3650 3200 2820 4060 2470 362o 2150 3160 1830 280i (Hinged Ends... 1620 Round Ends. . . r Ljght. 9 128 TABLES OF STRUTS. No. 5. PENCOYD I BEAMS AS STRUTS. GREATEST SAFE LOAD IN LBS. PEE SQUARE INCH OF SECTION. When the struts are secure from failure in the direction of the flanges, and. can bend only in the direction of the web C. D. Using factors of safety given in previous tables. SIZE CONDITION LENGTH IN FEET. OP BKAM OP TT-wTia JjjNDS. 2 4 6 8 10 12 14 16 18 6" Fixed Ends 14240 12900 11 580 10690 9840 8960 S9sn 7810 Flat Ends 14240 12900 '11580 10690 9840 8960 8270 7780 Heavy r = 2-31 Hinged Ends... Round Ends 13790 13160 1232010910 11520J 9900 9950 8710 9050 7630 8080 6580 7300 5730 6650 5030 6" Fixed Ends 14380 13030 mfio 10050 10090 9270 8KOO 8000 Flat Ends 1 WS;t 13030 11760 \ 10950 10090 9270 8500 7970 Light. . . Hinged Ends 113340 12460 11110 10230 1 93-20 8420 7580 6910 I =- 2-4S Round Ends. . . . 13330 11670 10140 9050 7930 6950 6040 5200 5" Fixed Ends 13840 13840 12270 12270 1104010000 1104010000 9040 9040 8230 7680 8220; 7640 7110 6900 Flat Ends... __ Heavy 'Hini> 11650 10330 9230 8160 7240 6470 5680 r = 1 Round Ends 12670 10750 9170 7820 6670 5660 4830 4030 K" Fixed Ends.... 14110 12650 11400 10340 9430 8580 1 8000 7500 J Flat Ends 14110 12650 1140010340 9430 8580 7970 7450 Li ff ht Hinged Ends 13640 12050 10720' 95901 Km 7670 MI in 6220 r = 2-0 Round Ends . . . 1300011210 9660 8260 7140 6130 5200 4560 | 4" Fixed Ends 1316011400 13160 11400 10090 10090 8880 8880 8040 8020 7370 7270 6750 6370 6130 5700 Flat Ends Heavy Hinged Ends.. 12610 10720 9320 8000 6970 6040 5170 4480 r = 1-63 Round Ends. . 11840 9660 7930 6490 5270 4380 3540 2870 A" Fixed Ends... 13160 11400 10170 8960 8090 7410 6830 6170 T: Flat Ends 1316011400 10170 8960 8070 7330 6490 5740 Light. . . Hinged Ends 12610 10720 9410i 8080 7040! 6100 5280 4530 r = 1-63 Round Ends 11840 9660 8040 6580 5350 4440 3650 2910 0" Fixed Ends... 1438ol 11760 10000 8500 7540 6710 5840 5030 4210 o Flat Ends j 143801 1 1760 10000 8500 7500 6310 5380 4390 3540 Heavy. . . . Hinged Ends. . . \ 13940 11110 9230 7580 6280 5110 4160J 3110 2280 r =1-21 Round Ends 13330 10140 7820 6040 4630 3490 2550 1790 1330 0" Fixed Ends 14520 12010 10170 8650 7680 6870 6050 5230 4450 o Light Flat Ends Hinged Ends... 14520 12010 10170 14090 11380 9410 8650 7640 7750 6470 6550 5610 4630 5340 4390| 3360 3790 2520 * = 1-26 Round Ends 13500 10440, 8040 6220 4830 3710 2780 1970 1460 TABLES OP STKUTS. No. 5. PENCOYD I BEAMS AS STRUTS. |A I 129 LB In the marginal columns r indicates the radius of gyration taken around axis A. B. When strut is hinged the pins are supposed to lie in the direc- tion A. B. Under the conditions stated the strut may be considered flat ended in direction A. B. LENGTH IN FEET. CONDITION SIZE 20 22 24 26 28 30 32 34 36 OF ENDS. OP BEAM. 7320 6910 6440 C010 5590 5150 4740 4290 3930 Fixed Ends... 7210 6600 (5020 5560 5080 4540 4090 3620 3280 Flat Ends O 5980 5390 4820 4350 3840 3260 2800 23(50 2080 Hinged Ends... Heavy. 4320 3760 3200 2730 2310 1900 1620 1370 1190 Round Ends . . . r = 2-31 7540 7110 6710 6310 5880 5470 5070 4650 4250 Fixed Ends... a" 7500 6900 6310 5880 5430 4930 4440 4000 3580 Flat Ends O 6280 5680 5110 4670 4210 3680 3160 2720 2320 Hintred Ends... Light. 4630 4030 3490 3050 2600 2190 1830 1570 1350 Round Ends r 2-43 6620 6090 5590 5110 4610 4130 3730 3340 2970 Fixed Ends... 5" 6210 5650 5080 4490 3960 3460 3100 2780 2500 Flat Ends ' 5010 3390 4440 2820 3840 2310 3210 1860 2680 2220 1550 1290 1950 1100 1690 940 1450 820 Hinged Ends... Round Ends Heavy. r =- 1-99 7030 6580 6090 5630 51501 4090 4250 3860 3500 Fixed Ends.... 5" 6780 6160 5650 5130 4540 4040 3580 3220 2900 Flat Ends 5560 3920 4960 3340 4440 2820 3900 2350 3260 1900 2760 1590 2320 2040 1350 1160 1800 1000 Hinged Ends... Round Ends Light. r =2-08 5510 4910 4290 3790 3310 2850 2500 2180 1900 Fixed Ends A" 4980 | 4260 3620 3160 2760 2420 2140 1910 1680 Flat Ends 3730! 2970 2360 1990 1670 1380 1180 1040 900 Hinged Ends... Heavy. 2230 1710 1370 1130 930 780 670 600 520 Round Eiids. . . . r = 1-63 5590 5000 4410 3860 3400 2940 2570 2240 1930 Fixed Ends 4t f 5080 4350 3750 3220 2830 2480 2190 1950 1720 Flat Ends 3840 3060 2480 2040 1730 1430 1220 1070 920 Hinged Ends... Light. 2310 1760 1440 1160 960 810 690 610 540 Round Ends r =1.65 3560 2940 2450 2000 1740 1520 1320 1120 990 Fixed Ends... 0" 2950 2480 2100 1780 1490 1220 1000 820 670 Flat Ends o 1840 1030 1430 810 1160 660 960 560 800 680 450 370 590 320 500 260 420 Hinged Ends... 230 Round Ends Heavy. r = 1-21 3760 3150 2R10 2180 1850 1630 1420 1220 1060 Fixed Ends... 0" 3130 2640 2230; 1910 1620 1350 1110 900 750 Flat Ends O 1970 1570 1240 1040 870 740 630 ; 550 460 Hinged Ends... Lieht. 1120 880 710 600 500 410 350 290 240|Round Ends r = 1-26 130 TABLES OF STEUTS. No 6. PENCOYD I BEAMS AS STRUTS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION. When the struts are free to bend at right angles to the web ; or in the weakest direction C. D. Using factors of safety given in previous tables. SIZE OP BEAM. CONDITION OP ENDS. LENGTH IN FEET. 2 4 6 8 10 12 14 16 18 15" Fixed Ends.... 14380 11760 10000 8420 7500 6670 5800 5000 4170 -L V Flat Ends 14380 11760 10000 8420 7450 6260 5340 4350 3500 Heavy r= 1-20 Hinged Ends... Round Ends 13940111110 1333010140 9230 7820 7500 5950 6220 4560 5G60 3440 4120 2510 306! 1760 2250 1310 1 V Fixed Ends 1411011400 9439 8000 7030 6090 5150 4250 3500 J. *J Light Flat Ends Hinged Ends... 1411011409 13640 10720 9433 8630 7970 6910 6780 5560 5650 4440 4540 3260 358( 2323 2900 1800 r= 1-08 Round Ends 13000 9660 7140 5200 3920 2820 1900 1350 1000 10" Fixed Ends... 14240 11670 9840 8330 7370 6530 5630 4820 4000 &.! Flat Ends 14240 11670 9840 8320 7270 6110 5130 4170 3340 Heavy Hinged Ends.. . 13790 11010 9059 7370 6040 4910 3900 2890 2130 r = 1-17 Round Ends 13160 10020 7630 5810 4380 3290 2350 1660 1230 10" Fixed Ends... 13840 11040 9110 7720 6710 5670 4740 3830 3060 I Flat Ends 13840 11049 9110 7680 6310 5180 4090 3190 2570 Light .... Hinged Ends. .. 13350 10339 8250 6530 5110 39501 2800 2020 1510 r = 1-01 Round Ends 12670 9170 6760 4890 3490 2390 1620 1150 850 10-i" Fixed Ends Plat Ends 14380 143 11760 1176C 10000 100CO 8370 8370 7450 7390 6620 6210 57HO 5280 4950 4300 4130 3460 Heavy, . . . Hinged Ends... 13910 11110 9230 7439 6160 5010 4060; 3010 2220 r = 1-19 Round Ends 13330 10140 7820 5880 4500 3390 2470 1730 1290 10 1 " Fixed Ends 13840 10950 8960 7590 6580 5510 4530 3630 2880 Flat Ends 13840 10950 8960 7540 6160 4989 3870 3010 2440 Light Hinged Ends... 1335010230 8080 6340 4960 37:30 8600 1880 1400 r = 87 Round Ends 12670 9050 | 6580 4690 3340 2230 1500 1060 790 10" Fixed Ends ... 13S4o' 10950 8960 7590 6580 5510 4530 3630 2880 L\J Flat Ends 1384010950 8960 7540 6160 4980 3870 3010 2440 Heavy. . . Ringed Ends . . . 1*350 10230 80SO 6340 49601 3730 2600 1880 1400 I = -98 Round Ends 12670 9050 6580 4690 33401 2230 1500 1060 790 I TABLES Or STRUTS. 3 31 No. 6. PENCOYD I BEAMS AS STRUTS. L !" In the marginal columns r indicates the radius of gyration taken around axis A. B. When the strut is hinged the pins are supposed to lie in the di- rection A. B. If the pins lie in the direction C. D. consider the strut flat ended by this table. LENGTH IN FEET. CONDITION SIZE 20 22 24 26 28 30 32 34 36 OF ENDS. OP BEAM. 3500 2880 2410 1960 1720 1500 1290 1090 980 Fixed Ends... 15" 2900 2440 2070 1750 1460 1200 970 800 650 Flat Ends 10 1800 1000 1400 790 1140 650 940 550 790 440 670 370 580 320 490 260 420 230 Hinged Ends... Round Ends Heavy. r = 1-20 2830 2400 2310 2000 1870 1650 1620 1340 1380 1060 1160 820 1000 670 860 520 740 430 Fixed Ends Flat Ends 15" 1370 1100 890 730 610 520 430 340 280 Hinged Ends... Light. 770 630 510 410 340 280 230 200 170 Round Ends. . . . r = 1-08 &340 2780 2730 2320 2270 1970 1870 1650 1640 1360 1410 1100 1210 890 1040 720 920 580 Fixed Ends Flat Ends... 12" 1690 1310 1080 890 740 630 540 450 380 Hinged Ends... Heavy. 940 740 620 510 410 350 290 240 210 Round Ends r = I'll 450 1940 1660 1400 1160 1000 850 720 Fixed Ends.... 10" 2100 1730 1390 1090 850 670 510 410 Flat Ends JL -i 1160 930 760 620 520 430 340 270 Hinged Ends... Light. 660 540 420 350 280 230 200 160 Round Ends r = 1-01 3430 2830 2360 1930 1690 1470 1260 1070 960 Fixed Ends 10 1 " 2850 1750 970 2400 1370 770 2d30 1120 640 1720 920 540 1430 770 430 1170 660 360 940 560 310 770 470 250 620 400 220 Flat Ends Hinged Ends... Round Ends Heavy. r= I-M 2290 1850 1560 1310 1070 930 780 670 Fixed Ends i n i " 1990 1620 1270 990 770 600 460 380 Flat Ends . . . lU^r 1090 870 700 580 470 390 300 240 HingedEnds... r L -^?7 620 500 390 320 250 210 170 150 Round Ends. . . . 2290 1850 1560 1310 1070 930 780 670 Fixed Ends... 1 f\tt 1990 1620 1270 990 770 600 460 380 '.'. Flat Ends JL W 1090 620 870 500 700 390 580 320 470 250 390 210 300 170 240 150 Hinged Ends... Round Ends.... Heavy. r = -98 132 TABLES OF STKUTS. No. 7. PENCOYD I BEAMS AS STRUTS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION. The strut is supposed to be free to bend in the weakest direction C. D. The radius of gyration is taken around A. B. SIZE OK CONDITION LENGTH IN FEET. BEAM. OF ENDS. 2 4 6 8 10 12 14 16 18 10" Fixed Ends... Flat Ends 1370010770 13700 10770 8730 8730 7450 7390 6400 5970 5310 4730 4290 3620 3430 2850 2710 2300 Liirht . . r "= -95 Hinged Ends... Round Ends 13200 12500 10040 , 8820 7839 6310 61(50 4500 4770 3150 3460 2040 1 2360 1370 1750 970 1300 740 9" Fixed Ends 13700 10860 8800 7500 6440 5390 4370 3500 2760 t/ Flat Ends 137001 10860 8800 7450 6020 4830 3710 2900 2340 Heavy Elinged Ends. .. 13200 10130 7910 6220 4820 3570 2440 1800 1330 r = -98 Round Ends 12500 8930 6400 4560 3200 2120 1420 1000 750 9" Fixed Ends.... 13430 10520 8370 7150 6010 4910 3860 3000 2340 u Flat Ends 13430 10520 8370 6960 5560 4260 3220 2530 2020 Light iinged Ends... 12900 9770 7430 5740 4350 2970 2040 1470 1110 r = -89 Round Ends 12170 8490 5880 4090 2730 1710 1160 830 630 C" r^ixed Ends 13."70 10770 8650 7410 6310 5270 4210 3370 i 2640 o ?lat Ends l.:57) 10770 8659 7339 5880 4680 3540 2800! 2250 Heavy ttngedEnds... 1305J 10040 7750 6100 4670 3410 2280 17101 1260 r = ! Sound Ends 12330 8820 6220 4440 3050 2010 1330 950 720 C" Fixed Ends... 3430 10430 8330 7110 5960 4820 3790 2940 2290 o Hut Ends 3439 10430 8320 6900 5520 4170 3160 2480! 1990 Light linged Ends... 9900 9680 7370 5680 4300 2899 1990 1430 1090 r '68 Round Ends 2170 8370 5810 4030 2690 1660 1130 810 620 Hit connected by triangular bracing ? k The radius of gyration as found on page , 'I 111, is 4. 21 inches. 1=51. T Safe load per square inch by Table No. 2 = 10,800 Ibs. 136 WKOUGHT IRON AND STEEL. But the angles will fail individually if the bracing is not suf- ficient. To determine the greatest distance apart for centres of bracing, consider each angle as a strut bearing 10,800 Ibs. per square inch of section. The least radius of gyration for a single angle is . 60 inch. By Table No, 2, the value of correspond- r ing to the pressure of 10,800 is 51, as found above. Therefore .60 x 51 = 30 inches, which is the greatest distance apart for centres of bracing. For properly designed struts of the fore- going section, the resistance per square inch may be ascertained approximately by means of table No. 18, page 158, although the former kind of column should be somewhat stronger than the latter per unit of section. STRUTS OF UNEVEN ANGLES. When uneven angles are used as struts, find the value of r by means of the least radius of gyration as found on page 99, and the corresponding resistance per square inch of section by table No. 2 as before. If the angle is braced in such a manner that failure cannot occur diagonally, it will then fail in the di- rection of the shortest leg, and if braced in this direction also, it will be forced to fail in the direction of the longest leg. The resistance in either direction can readily be found by means of the respective radii of gyration, as given in columns VII, VIII, IX, page 99. It is frequently desirable to use a pair of uneven angles, braced together in the direction of the shortest legs. Total length = L. v\S \P f- -----I' For this form the least radius of gyration for the combined TABLES OF STEUTS. 137 sections will be the same as the greatest radius of gyration for a single angle. Therefore take in the tables of elements of un- even angles, the greatest radius, or that corresponding to axis A B, when estimating the strength of the combined sections, and the least radius when determining the distance between cen- tres of bracing. Example. A flat-ended strut, 16 feet long, is composed of two uneven angles, each 6 x 4 x ^ inches, and 4.75 square inches sectional area. The angles are braced together in the direction of the short legs. What is the greatest safe load for the strut, and what the greatest distance between centres of bracing measured on the leg of the angle ? By the tables on page 99, the greatest radius of gyration = 1.9 inches, therefore L = 101. T By Table No. 2 we have for this 7,450 Ibs. per square inch, or 70,700 Ibs. for the whole strut. The least radius of gyration is .92 inch, which multiplied by 101 gives 92.9 inches as the greatest distance between centres of bracing. To find the greatest distance apart centres of bracing (I) should be it is only necessary to remember that should not exceed - . I = distance between bracing centres. r = least radius of gyration of single angle. L total length of strut. E = least radius of gyration of combined section. When struts of any section are hinged, in order to utilize the maximum efficiency of the strut it is of the utmost importance to keep the centre of pin in line with the centre of gravity of cross section of the strut. In the tables of elements 94-101, the positions of centres of gravity are accurately defined. 138 TABLES OF STRUTS. No. 9, PENCOYD ANGLES AS STRUTS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION USING THE FACTORS OF SAFETY OF PREVIOUS TABLES. SIZE OP ANGLE. CONDITION OP ENDS. LENGTH IN FEET. 2 4 6 8 10 12 14 16 4870 422.1 2930 1690 18 6"x 6" r= 1-18 Fixed Ends... Flat Ends Hinged Ends. .. Round Ends 14380 14:380 13940 13330 11670 11670 11010 10020 9920 9920 9140 7720 8370 8370 7430 5880 7410 7330 6100 4440 6580 6160 4960 3340 5710 5230 4010 2430 4060 3400 2180 1260 5"x5" r = -99 Fixed Ends .. Flat Ends Hinged Ends... Round Ends 13840 1:3840 13330 12670 11040 11040 10330 9170 8960 8960 8080 6580 7630 7590 6410 4760 6620 6210 5010 3390 5590 5080 3840 2310 4570 3920 2640 1530 3690 3070 1930 1090 2940 2480 1430 810 4"x 4" r = -80 Fixed Ends Flat Ends Hinged En ds... Round Ends. . . . 13030 13030 12460 11670 10090 10090 9320 7930 8000 7970 6910 5200 6750 6370 5170 3540 5470 4930 3680 2190 4250 3580 2320 1350 3280 2730 1650 920 2470 2120 1170 670 1870 1650 890 510 3f'x 3f r = -69 Fixed Ends Flat Ends 12520 12520 11920 11060 9270 9270 8420 6950 7370 7270 6040 4380 5920 5470 4250 2640 45?,0 '3870 2600 1500 asio 2760 1(570 930 2410 2070 1140 650 1790 1550 830 470 1400 1090 620 350 Hinged Ends. .. Round Ends 3"x3" r = 59 Fixed Ends.... Flat Ends Hinged Ends... Round Ends. . . . 11760 11760 11110 10140 8420 8420 7500 5950 6670 6260 5060 3440 5000 4350 3060 1760 3500 2900 2410 2070 1140 650 1720 1460 790 440 1290 970 580 320 980 650 420 230 2J"x2f" r = -64 Fixed Ends... Flat Ends Hinged Ends... Round Ends 11400 11400 10720 9660 8090 8070 7040 5350 6170 5740 4530 2910 4370 3710 2440 1420 2480 1430 810 1940 1730 9:30 540 1440 1140 640 360 1040 720 450 240 780 460 300 170 2f x2f T = -49 Fixed Ends Flat Ends Hinged Ends... Round Ends 11040 11040 10830 9170 7680 7640 6470 4830 5630 5130 3900 2350 3760 3K30 1970 1120 2410 2070 1140 650 1630 1350 740 410 1130 830 510 270 830 490 320 190 II" TABLES OF STRUTS. 139 No. 9. PENCOYD ANGLES AS STRUTS. A B . A- r in the marginal columns gives the radius of gyration for axis A B, or for either axis of the combined pair of channels. See de- scription, page 121. SIZE CONDITION LENGTH IN FEET. OP OF CHANNEL ENDS. 6 8 10 12 14 16 18 20 22 15" Fixed Ends 14110 13570 12900 12400 11890 11400 11040 Flat Ends 14110 1357d 12900 12400 11890 11400 iimn ia7 Hinged Ends... ..13640 13050 12320 11780 11240 10720 10330 Round Ends. luunn 1233,) 11520 10900 10290 9(i(iO 9HO 2.05 2.46 2.87 3.28 3.69 4.10 4.51 12"H'y Fixed Ends 14240 13570 12780 12140 ! 11580 11130 10600 10170 Flat Ends 14240 13570 12780 12140 11580 11130 10600 10170 10-3 J V Hinged Ends. .. 13790 13050 12190 115101091010420 9860 9410 d 7-5 Round Ends 13160 12330 11360 10600J 9900: 9290 8600 8J40 1.61 2.02 2.42 2.83! 3.23 3.64 4.C4 4.44 12"L't Fixed Ends.... 14240 13570 12780 1214011580 11130 10600 10170 r ==== 4 66 Flat Ends 14240 13570 12780 12140115801113010600 10170 J) - = 10-2 Hinged Ends... 1379;) 13350 1219:) 11510;i0910;i0420 9860 9410 d = 7-7 Round Ends 13160 1233:) 11360 10600 9900 9290 8600 8040 1.30 1.62 1.94 2.27 2.59 2.92 3.24 3.16 10"lTy Fixed Ends 1:3840 isnn 12140 11490 10950 10430 9920 9430 Flat Ends . 13840 12900 12140 11490 10950 10430 9920 ()4;->Q r = 3 "92 Hinged Ends 13350 12320 11510 10820 10230 9680 9140 8COO D= 9 * Round Ends. , 12670 1 ifwn lOfino 9780, 9050 8370 77 -'0 7140 d i==s 6 3 1.71 2.14 2.57 2.99 3.42 3.85 4.28 4.71 10"L't Fixed Ends 13700 12900 12140 11490 10950 10340 9840 9350 Flat Ends 13700 12900 12140 114UH 10950 10340 9840 9350 r ~^= 3 8 9 D= B ' Hinged Ends... Round Ends 13200 12320 12500J 11520 11510 10600 10820 9780 10230 9050 9590 8260 9050 7630 8510 7040 1.42 1.77 2.13 2.48 2.84 3.19 3.55 3.90 9"He'vy Fixed Ends 14240 13300 12400 11580 10950 10340 9760 9190 8650 r = 3-45 Flat Ends 14240 13300 12400 11580 10950 10340 9760 9190 8(>50 D- 8>1 d = 6-4 Hinged Ends. ..13190,12760 11780 Round Ends. ... 131(50 12000 l'900 10910 9900 10230 9050 9590 8260 8960 7530 83 6850 7750 6220 1.18 1.53 1.97 2.36 2.76 3.15 3.55 3.94 4.33 9 "Light Fixed Ends.... 14240 13300 12400 11580 10950 10340 9760 9190 8650 7-8 Flat Ends .14340,13300 12400 11580 10950 Hinged Ends.. .13790 12760 1178()il0910!10230 10340 9590 9760 89(50 01 '.'0 8330 8H5i 1 7750 d = 5- 8 Round Ends. . . . 131HO; 12000 10900 99001 9050 8260 7530 6850 6220 1.03 1.38 1.72 2.06 2.41 2.75 3.10 M, 3.78 TABLES OF STRUTS. 145 No. 12. LATTICED CHANNEL STRUTS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION, USING FACTORS OF SAFETY GIVEN IN PREVIOUS TABLES. The channels must be connected so as to insure unity of action and separated not less than the distances D or d respectively, given in inches in the marginal columns. Figures in heavy type under each length represent the greatest distances apart in feet on each channel that centres of lateral bracing should be placed. LENGTH IN FEET. CONDITION SIZE OF OF 24 26 28 30 32 34 36 38 40 ENDS. CHANNEL. 10690 10260 9920 9590 9190 8880 8580 8280 8090 Fixed Ends 15" 10690 10260 9920 9590 9190 8880! 8580 8270 807'0 Flat Ends r = 5. 51 9950 9500| 9140 8780 8330 8000j 7670 7300 7040 Hinged Ends... 8710 8150 7720 7330 6850 6490 1 6130 5730 5350 Round Ends . . . D 4.92 5.33 5.74 6.15 6.56 6.97 7.38 7.79 8.20 9760 9270 8880 8500 8230 7950 7720 7500 7240 Fixed Ends.... 12"H'y 9760 9270 8880 8500 822(, 7920 7680 7450 7080 Flat Ends ... r = 4 -56 8960 8420 8000 7580 7240 6840 6530 6220 5860 Hinged Ends.. 7530 6950 6490 6040 5CGO 5230 4890 4560 4210 Round Ends d= 7 . 5 4.85 5.25 5.66 6.06 6.47 6.87 7.28 7.68 8.09 9760 9270 8880 8500 8230 7950 7720 7500 7280 Fixed Ends... 12' Vt 9760 9270 8880 8500 8220 7920 7680 7450 7140 Flat Ends r - 4.56 8960 8420 8000 7580 7240 6840 6530 6220 5920 Hinged Ends... -r\ 10-2 7530 6950 6490 6040 5660 5230 4890 4560 4270 Round Ends 3.89 4.21 4.54 4.86 5.19 5.51 5.84 6.16 6.49 8960 8420 8140 7860 7590 7320 7070 6830 6580 Fixed Ends... 10"H'y 8960 8420 8120 7830 7540 7210i 6840 6490 6160 Flat Ends... 8080 7500 7100 6720 6340 5>80 5620 5280 4960 Hinged Ends... D'I -90 . Hinged Ends... r = -85 430 340 260 210 170 Round Ends. D = 2-4 10.12 11 13 12 14 13 Ifi 14 17 d = -64 1250 990 800 FiTod "Ends 2" 930 670 470 Flat Ends 560 420 310 Hinged Ends... r = -74 300 230 180 Round Ends. T) = 2 " * 8.38 9.22 10.05 d = 80 150 TABLES OF STRUTS. No. 15. PENCOYD CHANNELS AS STRUTS. GREATEST SAFE LOADS IN LBS. PER SQ. INCH OF SECTION, WHEN THE STRUTS ARE FREE TO BEND AT RIGHT ANGLES TO THE WEB OR IN THE WEAKEST DIRECTION, USISG FACTORS OF SAFETY GIVEN IN PREVIOUS TABLES. SIZE OP CHANNEL CONDITION OF ENDS. LENGTH IN FEET. 2 4 6 8 10 12 14 16 18 1 V Fixed Ends.... 14240 11580 9680 8180 7240 6350 5430 4570 3790 S-O Flat Ends 14240 11580 9680 8170 7080 5930 4880 3920 3160 Hinged Ends.. . 13790 10910 8870 7170 5S60 4720 3620 2640 1990 T = 1-13 Round Ends 13160 9900 7430 5490 4210 3100 2150 1530 1130 1 0" Fixed Ends 13570 10690 8580 7320 6220 5110 4060 3220 2520 LA Flat Ends 13570 10690 8580 7210 5790 4490 3400 2690 2160 Heavy I = -92 Hinged Ends... Round Ends 13050 12330 9950 8710 7670 5980 4580 6130 4320 2960 3210 4860 2180 1260 1610 900 1200 680 10" Fixed Ends... 12780 9590 7630 6220 4910 3660 2710 1980 1580 1 Flat Ends 12780 9590 7590 5790 4260 3040 2300 1760 1300 Light I = -74 Hinged Ends... Round Ends. . . . 12190 11360 8750 7330 6410 4760 4580 2960 2970 1710 1910 1070 1300 740 950 550 710 400 1 0" Fixed Ends... 13160 10260 8140 6910 5670 4530 3500 2660 2020 1U Flat Ends 13160 10260 8120 6600 5180! 3870 2900 2260 1790 Heavy. . . . Hinged Ends... 12610 9500 7100 5390 3950' 2600 1800 1270 970 r = -84 Round End*. . . . 11840 8150 5420 3760 2390 1500 1000 720 560 10" Fixed Ends 12400 9190 7320 5840 4410 3220 2340 1740 1360 1U Flat Ends 1->400 9190 7210 5380 3750 2690 2020 1490 1040 Light r = -69 Hinged Ends... Round Ends 11780 10900 8330 6850 5980 4320 4160 2550 2480 1440 1610 900 1110 630 800 450 600 340 Q" Fixed Ends 12400 9110 7240 5750 4330 3120 2240 1690 1320 y Flat Ends ! 12400 9110 7080 5280 3K60 2620 1950 1430 1000 Heavy Hinged Ends... 11780 8250 5860 4060 2400 1550 1U70 7',0| 590 r -= -6S Round Ends 10900 6760 4210 2470 1390 870 610 430 320 Q" Fixed Ends 11670 8370 6620 4910 3400 2310 1660 1240 940 V Flat Ends 11670 8370 081*. 4260 2830 2000 1390 920 600 Light Hinged Ends... 11010 74:30 5010 2970 1731 1100 760 560 390 r= -6 Round Ends 10080 5880 3390 1710 960 630 420 300 210 TABLES OF STKUTS. 151 No. 15. PENCOYD CHANNELS AS STRUTS. T. JU r in marginal columns is the radius of gyration taken around axis A B. When strut is hinged the pins are supposed to lie in the direction A B. When the pins are in the direction (J D, consider the strut flat ended by tliis table. LENGTH IN FEET. CONDITION OP ENDS. SIZE OF CHANNEL. 20 22 24 26 28 30 32 34 6 3120 26211 1550 870 1940 1730 930 540 1250 930 560 300 1650 1380 750 420 1050 73f 450 240 1020 690 440 230 710 400 260 160 2540 2170 1210 690 1640 1360 740 410 990 670 420 230 1350 1030 600 330 830 490 330 190 810 470 310 180 2070 1830 990 570 1360 1040 600 340 800 470 310 180 1070 770 470 250 670 370 240 150 1760 1520 820 460 1100 800 490 260 1520 1220 680 370 950 610 400 210 1300 980 580 320 790 4fiO 300 170 1090 800 490 260 970 640 410 220 840 500 330 190 Fixed Ends Flat Ends Hinged Ends. .. Round Ends . . . Fixed End? Flat Ends Hinged Ends... Round Ends Fixed Ends.... Flat Ends Hinged Ends... Round Ends Fixed Ends Flat Ends Hinged Ends... Round Ends Fixed Ends Flat Ends Hinged Ends... Round Ends Fixed Ends Flat Ends Hinged Ends. .. Round Ends.... Fixed Ends Flat Ends. . .. Hinged Ends... Round Ends 15" r = 1-13 12" Heavy. 12" Light. r -74 10" Heavy. 10" r W;, 9" Heavy. r -68 9" Light. r~ - '60 910 570 370 200 740 430 280 170 l I [::::: I 152 TABLES OF STRUTS. No. 16. PENCOYD CHANNELS AS STRUTS. GREATEST SAFE LOAD IN LBS. PER SQ. INCH OF SECTION WHEN THE STRUTS ARE FKEE TO BEND AT RIGHT ANGLES TO THE WEB OR IN THE WEAKEST DIRECTION, USING FACTORS OF SAFETY GIVEN IN PREVIOUS TABLES. SIZE OF CHANNEL CONDITION OF ENDS. LENGTH IN FEET. 2 4 6 8 10 12 14 16 18 Q" Fixed Ends... 12520 9350 7450 6010 4610 3400 2470 1840 1450 o Flat Ends 12520! 9350 7390 5.560 3960 2830 2120 1610 1150 Heavy. . . Hinged Ends. .. 11920: 8510 6160 4350 2680 1730 1170 870 650 r = -71 Round Ends . . . 11060 7040 4500 273U 1550 960 670 50C 360 Q" Fixed Ends 11760 8420 6670 5000 3500 2410 1720 1290 980 O Flat Ends 117'60 8420 6260 4350 2900 2070 1460 970 650 Light.... r = -60 Hinged Ends... Uoinul Ends . . . 11110 10140 7500 5950 5060 3440 3069 1760 1800 1000 1140 650 790 440 580 320 420 230 7" Fixed Ends 12140 8880 7030 5470 4000 2830 2000 1550 1170 I Flat Ends 12140 8880 6780 4930 3340 2400 J780 1260 860 Heavy Hinged Ends... 11510 8000 5560 3680 2130 1370 960 700 530 r = -66 Round Ends 10600 6490 3920 2190 1230 770 560 . 390 280 7" Fixed Ends.... 11670 8280 6490 4780 3280 2220 1610 1180 900 i Flat Ends 11670| 8270 6070 4130 2730 1940 1330 870 560 Light [linged Ends. .. 11010 7300 4860 2850 1650 1060 730 530 370 r = -5S Round Ends . . . 10020 5730 3240 1640 920 610 410 280 200 fi" ?ixed Ends 12270 9040 7190 5670 4210 3030 2150 1640 1270 u ?lat Ends 12270 9040 7020 5180 3540 2550 1890 1360 950 Heavy linged Ends... 11650 8160 5800 3! 50 2280 1490 1030 740 570 r = -7 lound Ends . . . 10750 6670 4150 2390 1330 840 590 410 310 fi" Hxed Ends. .. 11130 7770 5750 3890 2520 1690 1200 870 Flat Ends. 11130 7730 5280 3250 2160 1430 880 530 Light.... r -= -51 Hinged Ends... Round Ends . . . 10420 9290 6590 4960 401)0 2470 2060 1180 1-200 680 770 4:30 540 290 350 200 K" Fixed Ends... 11490 8140 6260 4530 3060 2020 1500 1070 820 u Flat Ends 114K) 8120 5830 3870 2570 1790 1200 770 480 Heavy Hinged Ends... 10820 7100 4620 2600 1510 970 670 470 320 r = -5 Round Ends . . . 9780 5420 3000 1500 850 560 370 250 180 TABLES OF STRUTS. No. 16. PENCOYD CHANNELS AS STRUTS. 153 r, in marginal columns, is the radius of gyration taken around axis A B. When strut is hinged, the pins are supposed to lie in the direction A B. When the pins are in the direction CD, consider the strut flat ended by this tuble. SIZE CONDITION LENGTH IN FEET. OP OP CHANNEL ENDS. 2 4 6 8 10 12 14 16 18 K" Fixed Ends 10600 7190 5000 3090 1870 1290 890 Flat Ends 10600 7020 4350 2600 1650 970 550 Light.... r = -45 Hinged E.ids.. . Round Ends . . . 9860 8(500 5800 4150 3060 1760 1530 860 890 510 580 320 3GO 200 A" Fixed Ends ... 11040 7080 5630 3760 2410 1630 1130 830 rr Flat Ends 11040 7640 5130 3130 2070 1350 8:30 490 Heavy. . . Hinged Ends.. . 10330 6470 3900 1970 1140 740 510 320 r = -50 Round Ends . . . 9170 2350 1120 650 410 270 190 A" Fixed Ends 10860 7500 5390 3500 2180 1500 1040 740 4: Flat Ends 10860 7450 4830 2900 1910 1200 720 430 Light .... Hinged Ends. . . 10130 6220 3570 1800 1040 670 450 280| r = -4b Round Ends . . . 8930 4560 2120 1000 600 370 240 170 0" Fixed Ends 10690 7320 5110 3220 1940 1360 950 670 o Flat Ends 10690 7210 4490 2690 1730 1040 610 370 Hinged Ends . . 9950 5980 3210 1610 930 600 400 240 '. '. '. '. '. r = -46 Round Ends . . . 8710 4320 1860 900 540 340 220 150 91" Fixed Ends 10340 6990 4690 2800 1730 1140 790 "4" Flat Ends 10340 6720 4040 2380 1470 840 460 ... Hinged Ends.. . 9590 5500 2760 1350 790 510 300 r = -43 Round Ends 8260 3870 1590 760 440 270 170 O" Fixed Ends. 8650 5190 2'90 1390 810 2 Flat Ends 8650 4590 2210 1080 480 Hinged Ends ! . 7750 3310 1230 62*. 310 r = -31 Round Ends . . . 6220 1940 700 350 180 154 TABLES OF STKUTS. WROUGHT IRON COLUMNS OR PILLARS OF ROUND AND SQUARE CROSS SECTION. Experiments on columns of this class are not very complete, especially as denoting the comparative values for the various end conditions. The following tables, Nos. 17 and 18, are derived partly from experiment on actual columns, extended and com- pleted by comparison with the experiments on rolled struts from which all our previous tables of strut resistances are derived. Table No. 2 is taken as the basis for the working values. On account of the more perfect symmetry of form possessed by round and square sections than the shapes for which table No. 2 was especially calculated, the safe loads per square inch of section are increased ten (10) per cent, for round columns, and five (5) per cent, for square columns. That is, the factors of safety pre- viously given remaining the same, the ultimate strength is sup- posed to be 10 and 5 per cent, respectively greater than the rolled struts. The tables are calculated for certain thicknesses of iron vary- ing from " for 2" diameter up to " for 12" diameter, as marked in the margins. At the same place R represents the radius of gyration for the diameter and thickness given. When the thickness varies but a little from that given, the strength per square inch of section can be accepted as practically unchanged. But when the variation becomes of importance, the radius of gyration corresponding to the altered thickness will have to be obtained, and the strength of the column then ascertained from table No. 2, as heretofore described. The following table gives the values of the radius of gyration for round and square columns from 2 to 12 inches diameter, and .from ^ of an inch to 1 inch thick. Example for Round Column : What is the greatest safe load for a flat-ended round column 6 inches outer diameter, |" thick, 8.64 sq. in. area, and 18 feet long, r^l.95 - =111. By table No. 2 the corresponding safe load = 6780 Ibs. + 10 per cent. = 7460 Ibs. per sq. inch of section, or 64,440 Ibs. for the column. For a square column add 5 per cent, to table No. 2, instead of 10 per cent, as above. TABLES OF STKUTS. 155 RADII OF GYRATION FOR ROUND COLUMNS. THICKNESS IN INCHES VARYING BY TENTHS. OUTSIDE DIAMETER .2 .3 .5 .6 .7 .8 .9 1.0 OP COLUMN IN INCHES. CORRESPONDING RADIUS OP GYRATION IN INCHES. 2 .67 .64 .61 .58 .56 .54 .52 .51 .50 .50 3 1.03 .99 .96 .93 .90 .88 .85 .83 .81 .79 4 1.38 1.35 1.31 1.28 1.45 1.22 1.19 1.16 1.14 1.12 5 1.73 1.70 1.66 1.63 1.6D 1.57 1.54 1.51 1.48 1.46 6 2.08 2.05 2.02 1.98 1.95 1.92 1.89 1.86 1.83 1.80 7 2.43 2.40 2.36 2.33 2,30 2.27 2.24 2.21 . 2.18 2.15 8 2.79 2.76 2.72 2.69 2.66 2.62 2 59 2.56 2.53 2.50 9 3.15 3.11 3.08 3.04 3.01 2.97 2.94 2.91 2.882.85 10 3.51 3.47 3.44 3.40 3.37 3.33 3.3J 3.27 3.23 3.20 11 3.86 3.82 3.79 3.75 3.72 3.68 3.65 3.62 3.583.55 12 4.21 4.18 4.15 4.11 4.08 4.04 4.01 3.97 3.94 3.90 RADII OF GYRATION FOR SQUARE COLUMNS. OUTER THICKNESS IN INCHES VARYING BY TENTHS. DIAMETER ACROSS .1 .2 3 .4 .5 .6 .7 .8 .9 1.0 FLATS IN INCHES. CORRESPONDING RADIUS OP GYRATION IN INCHES. 2 .78 .74 .71 .68 .65 .63 .61 .59 .58 .58 3 1.18 1.14 1.11 1.08 1.04 1.01 .98 .96 .93 .91 4 1.59 1.55 1.51 1.47 1.44 1 41 1.38 1.35 1.32 1.29 5 2.00 1.96 1.92 1.89 1.85 1 81 1.78 1.75 1.71 1.68 6 2.41 2.37 2.33 2.29 2.25 2.21 2.18 2.15 2.11 2.08 7 2 82 2.78 2.74 2.70 2.66 2.62 2.58 2.55 2.51 2.48 8 3. -23 3.19 3.15 3.11 3.07 3.03 2.9'.t 2.96 2.92 2.89 9 3.63 3 59 3.55 3.51 3.48 3.44 3 40 3.36 3.32 3 29 10 4.04 4.00 3.96 3.92 3.88 3.84 3.80 3.77 3.73 3.70 11 4.45 4.41 4.37 4.33 4.29 4.25 4.21 4.17 4.13 4.10 12 4.86 4.82 4.78 4.74 4.70 4.66 4.62 4.58 4.544.51 156 TABLES OF STRUTS. No. 17. ROUND COLUMNS. GREATEST SAFE LOADS IN LBS. PER SQ. IN. OF SECTION. By this table for the same ratios of - the safe loads are increased 10 per cent, over the results obtained for previous tables, as given in table No. 2. SIZE OUTKU DIAME- TER. CONDITION OF ENDS. LENGTH IN FEET. 2 4 6 8 10 12 13350 13350 12670 11660 12640 12640 12000 10890 11570 11570 10740 9330 9940 9940 8970 7330 8840 8820 7660 5790 7860 7050 6310 4490 6190 5640 4290 2580 3230 2720 1570 890 14 16 18 12" Diameter. 1" thick.. R=3-4 10" Diameter, i" thick.. R = 3-37 8" Diameter. i" thick.. R = 2-8 6" Diameter. f ' thick.. R=2-00 5" Diameter, f" thick . R = i-4 4" Diameter. J" thick.. R^l 33 3" Diameter. W thick. R = i-oo 2" Diameter I" thick.. ll=- Fixed Ends 15220 15220 14680 13940 14630 14630 140:30 13200 13490 13490 12810 11820 12140 12140 113(50 10080 11090 11090 10250 8720 9940 9940 8970 7330 8440 8400 7110 5310 6140 5f>80 4220 2540 14.330 14330 13700 12840 13490 13490 12810 11820 12440 12440 11680 10480 11000 11000 10150 8600 9850 9850 8880 7230 8740 8710 7520 5750 7330 6880 5560 3780 4510 37^0 2420 1390 12640 12640 12000 10890 11940 11940 11140 9820 10730 10730 9850 8-280 9050 9040 7960 6220 8150 8060 6710 4880 7040 6560 5240 3460 5110 4400 2990 1720 2290 2020 1100 630 12040 12040 11250 9950 11280 11280 10450 8960 9940 9940 8970 7330 8440 8400 7110 5310 7460 7260 5920 4130 6190 5640 4290 2580 41:30 3440 2160 1230 17IX) 1440 790 440 11470 11470 10840 9200 10640 10640 9750 8170 9200 9200 8170 6460 7860 7650 6310 4490 6740 6270 4920 3150 5400 4680 3260 1880 3300 2780 1610 910 1340 990 600 330 Flat Ends Hinged Ends.. . Round Ends Fixed Ends Flat Ends .... 15660 15660 15160 14470 14770 14770 14190 13380 13490 13490 12810 11820 12540 12540 11790 10620 11570 11570 10740 9330 9940 9940 8970 7330 7820 7590 6240 4430 Hinged Ends... Round Ends. . . Fixed Ends Flat Ends Hinged Ends.. Round Ends. Fixed Ends Flat Ends Hinged Ends . 15220 15220 14680 13940 14470 14470 13870 13020 13490 13490 12810 11820 12140 12140 11360 10080 9850 98.50 8880 7230 Round Ends. Fixed Ends Fhit Ends Kin ired Ends... Round Ends Fixed Ends Flat Ends Hinged Ends Round Ends Fixed Ends Flat Ends Hinged Ends . , Round Ends. . . Fixed Ends. .. Flat Ends.. .. Hinged Ends* . . Round Ends. . . 15220 15220 14680 13940 13490 13490 12810 11820 TABLES OF STRUTS. 157 No. 17. ROUND COLUMNS. GREATEST SAFE LOADS IN LBS. PER SQ. IN. OF SECTION. The calculations are based on the thicknesses and radii of gyration marked under the diameters on marginal columns. See description. LENGTH IN FEET. CONDITION OP ENDS. SIZE OUTER DIAME- TER. 20 22 24 26 28 30 32 34 36 10910 10370 9850 9350 8990 8640 8340 8050 7770 Fixed Ends 12" 10910103701 9850 9350 8980 8610 8290 79HO 7520 Flat Ends Diameter. 10050 8490 9-160 8880 8330 7850) 7230 ! 6640 7880 6030 7390 5610 6970 5150 6570 4750 6180 4370 Hinged t nds.. . Round Ends |" thick. R 3-94 10020 9430 8990 8620 8:50 7910 76CO 7280 6940 Fixed Ends... 10" 10020 9430 8980 8610 8190 7720 7260 6830 6460 Flat Ends Diameter. 9070 8430 78SO 7390 6840 6380 6980 5510 5130!Hinged Ends. . . *" thick. 7430 6740 6030 5610 5010 4560 4130 3730 3350 Round Ends R = 3 ' 37 811 8740 8290 7860 7460 7040 6610 6190 5790 5400 Fixed Ends... 8710 8250 r .650 7070 6560 6110 5640 5140 4680 Flat Ends Diameter. 7520 5750 6900 5090 6310 4490 5920 3960 5240 3460 4780 3000 4290 2580 3750 2210 3260 Hinged Ends... 1880 1 Round Ends i" thick. XV ~ ^ ' ** 7330 6740 6190 5660 5110 4580 4130 3700 3300'Fixed Ends... 6" 6880 6:70 5640 4990 4400 3850 3440 3C80i 2780 Flat Ends Difimeter. 5560 3780 4920 3150 4290 2580 3580 2090 2990 1720 2470 1440 2160 1230 1880 1C40 161()iHiiigedEids... 910.Round Ends | thick. R = a-uo 6100 5440 4760 4210 3670 3160 2^90 2420 2110 ! Fixed Ends 5" 55301 4730 1 4020 3500 3050 2680 2380 2110 1870!Flat Ends Diameter. 4160 2490 33101 2640 1900 1520 2220 1260 1850 1030 1540 860 1330 750 1150 660 1000 580 H nged Ends... Round Ends StfRft 4580 3880 3260 2770 2320 2000 1780 1560 1360 Fixed Ends... . 4" 3850 3210 2750 2370 2040 1740 1470 1220 1010 Flat Ends Diameter. 2470 1440 2000 1110 1590 900 13:0 740 1110 630 940 530 800 450 690 380 610 330 Hinged Ends... Round Ends. . . . i" thick. R= i'33 2650 2100 1790 1500 1240 1070 910 770 Fixed Ends.... 3" 2270 1850 1480 1150 910 710 530 440 Flat Ends Diameter. 1250 1000 810 670 560 460 3.50 2801 .., Hinged Ei els.. . -fa" thick. 710 580 450 370 290 2501 200 170 Round Ends R=i-oo 1040 810 Fixed Ends.. .. 9" *"* 680 470 Flnt Ends 440 300 240 180 1 Hinged Ends... Round Ends.. . . Dintn^tcr. t" thick. T? _ 66 1 J\ 158 TABLES OF STEUTS. No. 18. SQUARE COLUMNS. GREATEST SAFE LOAD IN LBS. PER SQUARE INCH OF SECTION. By this table for the same ratios of , the safe loads are increased 5 per cent, over the results obtained in table No. 2. SIZE OF COLUMN. CONDITION OP ENDS. LENGTH IN FEET. 2 4 10330 10330 9500 8010 12160 12160 11460 10400 13540 13540 12940 12100 14390 14390 13860 13120 14950 14950 14480 13820 6 8 6760 6320 5060 3360 8690 8680 7660 6020 10330 10330 9500 8010 11310 11310 10540 9260 12160 12160 1 1460 10390 13540 13540 12940 12100 14380 14380 13S60 13120 14950 14950 14480 13820 10 12 14 16 18 2" i" thick.. R = 3" ^thick 4" }" thick.. R= 1-53 5" t" thick.. R = ! 6" t" thick.. .R=2-30 8" J" thick.. R = 3-07 10" i" thick.. R=3-7 12" 4" thick.. R = 4-56 Fixed Ends.... Flat Ends 13540 13540 12910 12100 14950 14950 14480 13810 8160 8120 6920 5210 10330 10330 9500 8010 11690 11690 10940 9750 12610 12610 11950 10960 13540 13540 12940 12100 14670 14670 14170 13470 5410 4770 3420 2000 7690 7570 6280 4540 9010 9010 8050 6440 10250 10250 9410 7910 11220 1122G 10450 9150 12480 12480 11800 10800 13540 13>40 12940 12100 14250 14250 13700 12950 4130 i 3440 2180 1250 6760 6323 5060 3360 8150 8HO 6920 5210 9170 9170 8220 66:30 10330 10330 9500 8010 11690 11690 10940 9750 12750 12750 12090 11130 13420 13420 12800 11930 3090 2600 1500 850 5830 5280 3980 2380 7420 7180 5900 4180 8400 8370 7260 5460 9410 9410 84*0 6910 10950 10950 10160 8790 12060 2060 1360 10270 2750 2750 12090 11130 2310 2020 1100 630 4920 4240 2900 1680 6720 6220 5010 3310 7780 7700 6400 4660 8690 8680 7660 6020 10250 10250 9410 8010 11400 11400 10(540 9380 12140 12140 11460 10400 1790 1510 820 450 4080 3410 2160 1240 6040 5540 4260 2590 7260 6930 5660 3950 8160 8120 6920 5210 9650 9650 8750 7190 10860 10860 10070 8670 11690 116M) 10940 9750 Hinged Ends... Round Ends Fixed Ends Flat Ends Hinged Ends... Round End* Fixed Ends Flat Ends . Hinged Ends.. . Round End* Fixed Ends Flat Ends Hinged Ends. .. Round Ends Fixed Ends Flat Ends Hinged Knds Round Ends Fixed Ends Flat Ends. .. rlinged Ends Round Ends. . Fixed Ends ... Flat Ends Hinged Ends... Round Ends Fixed Ends.... Flat Ends Hinge< 1 Ends. .. Round Ends. . . TABLES OF STR No. 18. SQUARE COLUM GREATEST SAFE LOAD IN LBS. PER SQUARE The calculations are based on the thicknesses and radii of gyration, marked under the diameters in marginal columns-. See preceding descrip- tion. LENGTH IN FEET. CONDITION SIZE 20 22 24 26 28 30 j 32 34 36 OP ENDS. OP COLUMN. 1440 1120 930 760 Fixed Ends.... 0" 1100 810 580 430 Flat Ends J 640 490 360 260 380 210 270 170 Hinged Ends... Round Ends I" thick. K- " 8380 2770 2290 1910 1660 1430 1210 1060 910 Fixed Ends... 0" 2820 2360 2010 1670 1370 1090 880 710 560 Flat Ends o 16901 1320 1090 900 750 630 550 450 370 Ringed Ends. .. tV' thick 950 760 630 510 420 360 290 240 210 Round Ends R= > 5370 4670 4080 3540 3020 2650 2250 1960 1770 FMxed Ends. ... A" 4710 3980 3110 2940 2560 2270 1980 1730 1500 Flat Ends TE a37o 1950 8850 1530 2160 1240 1800 1000 1470 830 1260 710 1080 620 930 540 810 450 linged Ends. .. iound Ends i" thick. R- * 6670 6130 5580 5020 4500 4020 3570 3150 2790 Fixed Ends.... K' 2590 Hinired Ends... Round Ends. . . . *" thick. R=3'OT 10330 9820 9320 8790 8490 8200 7920 7640 7340 Fixed Ends... 10" 10330 98-20 9320 87W 8470 8170 7870 7500 7060 Flat Ends J.U 9500 8010 8!40 7390 8400 6810 7800 6170 7390 5620 6980 5280 6590 4860 6220 4480 5780 4060 Hinged Ends. .. Round Ends.... i" thick. R=8-8T 11130 10680 10250 9730 9320 8920 8640 8350 8110 Fixed Ends... 1 9" 11130!10680 10250 9730 9320 8920 8630 8320 8060 Flat Ends 1 ft 10350 9030 9880 8440 9410 7910 8840 7300 8400 6810 7960 6340 7600 5940 7180 5490 6860 5130 Hinged Ends... Round Ends.... f" thick. R=4-65 160 WROUGHT IRON AND STEEL. RIVETS AND PINS. Rivets must be proportioned with sufficient bearing surface to resist crushing, and sufficient sectional area to resist shearing. Pins must be proportioned likewise, and also to safely resist the bending action which usually exists, owing to the centres of pressure being some distance from the centres of supports. The effective bearing area of a rivet or pin is equal to its di- ameter multiplied by the thickness of the surface it bears on. The shearing area is the area of the cross section of the pin or rivet for single shear, or double that section for double shear. For pins, the pressure on the pins multiplied by the leverage with which it acts on the pin supports is the bending moment. (See bending moments, page 78.) The ultimate crushing strength of wrought iron is taken as equal to its tensile strength, viz., 50,000 Ibs. per square inch, the shearing strength at -ft,- of same, viz., 40,000 Ibs. per square inch. The ultimate modulus of rupture is taken at 50,000, which is a fair estimate for cylindrical sections, as the average of many experiments we have made on that shape gives nearly that amount. The annexed table gives the ultimate resistance for single shear, or the area of the pin multiplied by 40,000, and the ultimate resistance to crushing, for each inch in thickness of bearing surface, or the diameter of the pin multi- plied by 50,000. The ultimate bending moments in inch Ibs. correspond to the given diameter of pins, and are derived from the formula 50,0007 M. = ~ . radius which can be reduced to this form, M = 6250 x area x diameter, all in inches. To obtain the working resistances, these ultimate values must be divided by the factor of safety desirable to use. The following proportions of the ultimate strength are com- monly used for the purposes named. RIVETS AND PINS. 161 For K. R. bridges, For light highway bridges, For roof trusses, etc., of ultimate strength, of " " of " Example. A pin has its supports located three inches apart, and bears a load of 100,000 Ibs. in the middle. What should the diameter of the pin be for a safety factor of five ? Bending moment = 100>00 ^ x 3 " = 75,000 inch Ibs. The nearest diameter corresponding to this and taking 3 of the tabular moments, is 4^ inches. The bearing value of this pin is ( of table) 42,500 Ibs. per inch of length, consequently the thickness of the metal which forms the pin bearings should be -^W 1 , or not less than 2.3 inches. For shear the pin has a large excess of strength, which will usually be found the case if properly proportioned other- wise. 11 162 WROUGHT IRON AND STEEL. ULTIMATE STEENGTH OF RIVETS AND PINS OF WROUGHT IRON. For the working strength divide the tabular figures by the desired factor of safety. DIAMETER IN INCHES OF RIVET OR PIN. AREA IN SQUARE INCHES. ULTIMATE STRENGTH FOR SINGLE SHEAR IN LBS. ULTIMATE CRUSHING STRENGTH PER INCH THICKNESS OF BEARING SURFACE. ULTIMATE BENDING MO- MENT IN INCH LBS. X .196 7840 25000 614 .248 9920 28125 873 y .307 12280 31250 1199 ii .371 14840 34375 1595 % .442 17680 37500 2073 \\ .518 20720 40625 2632 % .601 24040 43750 3287 1 inch. .785 31400 50000 4906 % .994 39760 56250 6993 * 1.227 49080 62500 9586 % 1.485 59400 68750 12762 % 1.767 70680 75000 1H566 % 2.074 82960 81250 21065 % 2.405 96200 87500 26305 % 2.761 110440 93750 32357 2 inches. 3.141 125660 100000 39263 % 3.547 141880 106250 47109 X 3.976 159040 112500 55913 4.430 177200 118750 65757 % 4.908 196320 125000 76688 % 5.412 216480 131250 88792 K 5.940 237600 137500 102094 6.492 259680 143750 116825 3 inches. 7.068 282720 150000 132426 ^ 7.670 806800 156250 149694 % 8.296 331840 162500 168514 % 8.946 357840 168750 188705 9.621 384840 175000 210459 % 10.321 412840 181250 233835 & 11.045 441800 187500 258909 % 11.793 471720 193750 285613 4 inches. 12.566 502640 200000 314150 * 13.364 534560 206250 344540 14.186 567440 2125CO 376816 % 15.033 601320 218750 411057 % 15.904 636160 225000 447300 % 16.800 672000 231250 485623 * 17.721 708840 237500 526092 18.665 746600 243750 568700 5 inches. 19.635 785400 250000 613600 20.629 825160 256-250 660773 IX 21.648 865920 26-2500 710326 % 22.691 907640 268750 762266 IX 23.758 950320 275000 816667 / 24.850 994000 281250 873627 y 25.967 1038680 287500 933189 6 inches. 27.109 28.274 1084360 1130960 21)3750 300000 995410 1060277 STRESSES IN TEAMED STEUCTURES. 163 STEESSES IN SOME SIMPLE FORMS OF FRAMED STRUCTURES. Compression indicated by the sign and by solid lines. Tension by the sign + and by dotted lines. When the prefix "stress" is used, the load borne by the member is indicated; otherwise the length of the member is meant. CRANES. Supported at the points A and B, maximum longitudinal stresses, due to weight W, suspended at the end. These stresses are modified by the position of the hoisting chain. FIG.1 E/ D is the point where a line drawn from C at right angles to A B will intersect the latter. Stress AC=+ -? x W Stress B G = x W " AB= + x TF in Fig. 2, or = - x TFinFig.3. .0. Jj *a. _D When point A is supported by inclined back stays as shown in Fig. 1, and when the back stay is in the plane of A B and W Stress A E = + ~ x W x 4- yl JD _fy JrJ and a resulting compression ensues on A B = ~ - x W x 164 WROUGHT IBON AND STEEL. CRANES. CD FIG.4 Stress CD=- 'AD W v " E D = - stress D 0. Let w = the horizontal reaction at B CD w = AB xW B E Stress B E = + -=-= x J2J JJ A E = + --, x (stress CD - w) E and H are points where lines drawn from D intersect at right angles A C and A B. X, Y and Z are the angles formed by extending the braces CD and B D as indicated by dotted lines, w = the hori- zontal reaction at B AB Stress A C= + ^ x W. Stress C D = - C D A D= or = + B H x w stress C D x - stress B D x BD Sine T Sine JT Sine F SineZ BD STRESSES IN FRAMED STRUCTURES. 165 TRUSSED GIRDERS. Weight in Middle. FIG. 6 Stress A C or fty B D ^ .AC W W " DC=-W Weight out of Centre. FIG. 7 w, AB x = - w FIG. 8 W. W. o Stress A HOT DU = + xW Stress B H or C E-- W 166 WKOUGHT IRON AND STEEL. TRUSSED GIRDERS. Unequal Loads W and w. FIG. 9 Stress as below on counter diagonals B E orHC according to position of greatest load. CH fW-w\ Stress <7tf= FIG. 10 Fink Truss. Stress B For D H W E O = -2 W ID stress 1 '= -14 Wx Stress ^1 jPor HE= AO STRESSES IN FRAMED STRUCTURES. 167 ROOFS. w load concentrated on each triangular apex. Strut Stresses. Stress D F= - w F B G Stresses on Ties. Rafter Stresses. =: + l|w x Stress CE=- 2 w C JT 168 WROUGHT IRON AND STEEL. ROOFS. w load concentrated on each triangular apex . Strut Stresses. ^ Fla ' 2 Bto-HInXL*-** (w) ^-SS i \ ! i ~ \ / V \~T> -r\ n Stresses. ft K- C B CD\ - - x - M 'x JTB; -_ Iw CB CD ---*- W * Stresses on Ties. Stress 6^ /or (7 i = + -5- x 77-^ x 7^-^ DB C B 1BI=+ w x CB CI = X -~ X ^ L = the sum of the stresses on F E and ^ /. L B = the sum of the stresses on E L and G L. STRESSES IN FRAMED STRUCTURES. 169 ROOFS. w = load concentrated on each triangular apex. The rafters and horizontal tie being each uniformly subdi- vided. Strut Stresses. -.f x*f Vertical Ties. Stress ^ if = + Stress i> / = + i/;. Stress G B = Rafter Stresses. n * Stress C D = -2 wx^ L -D ft A " D E =. 2i w Stress at B = + 2 w x Horizontal Tie. BA B G B 1= + stress at B + I stress D B x + (> 170 WROUGHT IRON AND STEEL. WROUGHT IRON SHAFTING. (For steel shafting see page 29.) The ultimate resistance of wrought iron to shearing averages about -ft of its ultimate tensile strength, i.e., about 40,000 Ibs. per sq. inch of section. The torsional resistance of any wrought-iron shaft can be determined when the shearing resist- ance is known ; thus, T= .196 d*s for round shafts, (a) T = . 28 d*s for square shafts. (b) d diameter of the shaft in inches. s = shearing strength in Ibs. per sq. inch. T the torsional moment in inch-lbs., that is, the force in Ibs. multiplied by the length in inches, of the lever through which the force acts. Taking s at 40,000 Ibs., and assuming that in machinery the working value of wrought iron should be taken at from one- fourth to one- fifth of its ultimate strength, these being factors of safety sanctioned by good practice, we adopt the mean of the two, which makes the working resistance to shearing = 9,000 Ibs. per sq. inch. Putting this in terms of the torsional moment and of the diameter, we derive from equations a and b, T = 1760 d 3 for round shafts, (c) T = 2520 d 3 for square shafts, (d) 3 / T y .p^Q for round shafts, d 4/ ^KOA f r square shafts. (/) Example 1. What should be the diameter of a round wrought SHAFTING. 171 iron shaft to safely resist a force of 1,000 Ibs. acting through a lever 30 inches long ? -4T 1000 x 1700 = 2.6 inches diameter. These formulae apply to shafts subject to twisting strains alone. In practice, however, sucn cases seldom occur, as shafts are generally subjected to combined bending and twisting strains. As there are no experimental data for such a combination of forces, we have to rely on analysis, which gives the following: = M + yf\ fj"p d = y for shafts carrying pulleys, etc., (o) I = ^720 2 for bare shafts, (p) I = \/l4Qd' 2 for shafts carrying pulleys, etc., - (q) SHAFTING. 175 In the event of the whole power being received on a principal shaft, the proper size of the shaft can be estimated direct by formula (g). Example 4. A principal shaft receiving 150 HP from the engine, revolves 150 R. P. M., and is continuous over bearings located 6 feet apart, the centre of main pulley being 24 inches from one bearing and 48 inches from the other. The effective loa 1 at the centre of the pulley resulting from weight of pulley and shaft, and tension of belt, is 1500 Ibs. What should be the diameter of the shaft ? Note. Excepting special cases which rarely occur in practice, it is best to treat such shafts as non-continuous. By rule 5, page 79, we have, Jf = WOOx:S4x_48 tit and by formula (7t) we have, 150 then, by formula (g) we have T>= 24000 + ^24000 2 + 63000" = 92290 inch-lbs. and by formula (), BELTING. When designing shafting, allow for the tension of belting, 50 Ibs. per inch of width for single leather belt or its equivalent, or 80 Ibs. per inch of width for double leather belt, or its equi- valent of other material. 176 WROUGHT IRON AND STEEL. WORKING PROPORTIONS FOR CONTINUOUS SHAFTING. TRANSMITTING POWER, BUT SUBJECT TO NO BENDING ACTION EXCEPT ITS OWN WEIGHT. DIAMETER or SHAFT IN INCHES. MAX. SAFE TOR- SIONAL MOMENT IN INCH-POUNDS. REVOLU' 100 [IONS PER MINUTE. 150 | 200 MAX. DIS- TANCE IN FEET BETWEEN BEARINGS. HP HP HP H 5940 6 10 14 11.7 If 7552 9 13 17 12.4 n 9433 11 16 21 13.0 tt 11602 13 20 26 13.6 2 14080 16 24 32 14.2 2i 16892 19 29 38 14.8 at 20048 23 34 46 15.4 2| 23580 27 40 54 16.0 3i 27500 31 47 63 16.5 2* 36603 42 62 83 17.6 3 47520 54 81 108 18.6 3i 60417 69 103 137 19.7 &i 75460 86 129 172 20.7 81 92812 105 158 211 21.6 4 112640 128 192 256 22.6 SHAFTING. 177 WORKING PROPORTIONS FOR CONTINUOUS SHAFTING. TRANSMITTING POWER, AND SUBJECT TO BENDING ACTION OP PULLEYS, BELTING, ETC. DIAMETER OF SHAFT IN INCHES. MAX. SAFE TOR- SIOVAL MOMENT IN INCH-POUNDS. REVOLUI 100 'IONS PER " 150 MINUTE. 200 MAX. DIS- TANCE IN FEET BETWEEN BEARINGS. HP IIP HP H 5940 5 7 10 6.8 If 7552 6 9 12 7.2 if 9432 8 11 15 7.5 if 11602 9 14 19 7.9 2 14080 11 17 23 8.2 w 16892 14 21 27 8.6 SH 20048 16 24 33 8.9 2| 23580 19 29 38 9.2 2* 27500 22 33 45 9 6 SI 36603 24 36 48 10.2 3 47520 39 58 77 10.8 3i 60417 49 74 98 11.4 8* 75460 61 92 123 12.0 3| 92812 75 113 151 12.5 4 112640 91 137 183 13.1 12 178 AEEAS AND CIRCUMFERENCES OF CIRCLES. TABLE OF CIRCLES. Circumferences or areas intermediate of those in the table, may be found by simple arithmetical proportion. The diameters, etc., are in inches ; but it is plain that if the diameters are taken as feet, yards, etc., the other parts will also be in those same measures. DlAM. INS. ClR- CUMP. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMP. INS. AREA. BQ. INS. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. 164 .049087 .00019 1 15-16 6.P8684 2.9483 4 15-16 15.5116 19.147 1-32 .098175 .0 077 2. 6.28319 3.1416 5. 15.7080 19.635 3-64 .147262 .00173 1-16 6.47958 3.3410 1-16 15.9043 20.129 1-16 .196350 .00807 1-8 6.67588 3.5466 1-8 16.1007 20.629 332 .291524 .00690 3-16 6.87223 3.7583 3-16 16.2970 21.135 1-8 .3'.2699 .01227 1-4 7.06858 3.9761 1-4 16.4934 21.648 5-32 .4.90374 .01917 516 7.26493 4.2000 5-16 16.6S97 2-2.166 3-16 .589149 .02761 3-8 7.46128 4.4301 3-8 16.8861 22.691 7-32 .687223 .03758 7-16 7.65763 4.6664 7-16 17.C824 23.221 1-4 .7V5398 .04909 1-2 7.85398 4.9087 1-2 17.2788 23.758 9-32 .8^3573 .06213 9-16 8.05033 5.1572 9-16 17.4751 24.301 5-16 .981748 .07670 5-8 8.24U68 5.4119 5-S 17.6715 24.850 11-82 .07992 .09281 11-16 8.44303 5.6727 11-16 17.8678 25.406 3-8 .17810 .11045 3-4 8.68938 5.9896 3-4 18.0642 25.967 13-32 .27627 .12962 13-16 8.83573 6.2126 13-16 18.2605 26.535 7-16 .37445 .15033 7-8 9.032 8 6.4918 7-8 18.4569 27.109 15-32 .47262 .17257 15-: 6 9. 22*43 6.7771 15-16 18.6532 27.688 1,2 .57080 .19635 3. 9.42478 7.0686 6. 18.8496 28.274 17-32 .66897 .2-1166 1-^6 9.6-2113 7.8662 " '1-8 19.2423 29.465 9-16 .76715 .24850 1-8 9.81748 7.6699 l-l 19. (535!) 30.6SO 19-32 .86582 .27688 3-16 10.0138 7.9798 3-8 20.0277 31.919 5-8 .96350 .30:580 1-4 10.2102 s.2958 1-2 20.4204 33.183 21^32 2.061-67 .33824 5-16 10.4065 8.6179 5-8 20.8131 34.472 11-16 2.15984 .37122 3-8 10.6029 8.941)2 3-4 21.2058 3->.785 23-32 2.25802 .40574 7-16 10.7992 9.2806 7-8 21.5984 37.T22 3-4 2. .35619 .44179 1-2 10.9956 9.6211 7. Ol Q(j 1 1 38.485 25-32 2.45487 .47937 9-16 11.1919 9.9678 1-8 22:3888 o9 871 13-16 2.55254 .51849 5-8 11.3883 10.321 1-4 22.7765 41.282 27-32 2.65072 .55914 11-16 11.1 5846 10.680 3-8 23.1692 42.718 7-8 2.74889 .60132 3-4 11.7810 11.045 1-2 23.5619 44.179 29-32 2.84707 .64504 13-16 11.9173 11.416 5-8 23.9546 45.664 15-Ki 2.! '4524 .69029 7-8 12.1737 11. 793 3-4 24.3473 47.173 31-32 3.04342 .73708 15-16 1-2.3700 12.177 7-8 24.7400 48.7'()7 1. 3.14159 .78540 4. 2.5664 12.566 8. 25.1327 50.265 1-16 3.33794 .88664 1-16 12.7627 12. 58.426 3-8 4.31969 .4849 3-8 3.744'> 15.033 3-4 27.4889; 60.132 7-16 4.51604 .62:50 7-16 3.9108 15.466 7-8 27.8816! 61.862 1-2 4.71239 .7671 1-2 4.1372 15.904 9. 28.2743 1 63.617 9-16 4.90874 .9175 9-11) 4.3335 16.349 1-8 28.6670: 65.397 5-8 5.1H509 2.0739 5-8 4.5299 16.800 1-4 29.0597 67.201 11-16 5.:-:Ol44 2.2365 11-16 4.7262 17.257 3-8 29.4524; 69. (129 3-4 5.49779 2.4053 34 4.92-26 17.721 1-2 29.84511 70.882 13-16 5.69414 2.5802 13-16 5.11K9 18.190 5-8 30. 2378 l 72.760 . 7-8 5.89049 2.7612 7-8 5.3153 18.665 3-4 30.6305 74.662 AREAS AND CIRCUMFERENCES OF CIRCLES. 179 TABLE OF CIRCLES Continued. DlAM. INS. Cm- CUMF. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. 9 7-8 31.0232 76.589 16 3-4 52.6217 220.35 23 5-8 74.2201 438.36 10. 31 .4159 78.540 7-8 53.0144 223.65 3-4 74.6128 443.01 1-8 31.8086 80.516 17. 53.4071 226.98 7-8 75.0055 447.69 1-4 32.2013 82.516 1-8 53.7998 230.33 21. 75.3982 452.39 3-8 32.5940 84.541 1-4 54.1925 233.71 1-8 75.7909 457.11 1-2 3-2.9867 86.590 3-8 54.5*52 237.10 1-4 76.1836 461.86 5-8 33.3794 88.664 1-2 54.9779 240.53 3-8 76.5763 466.64 3-4- S3. 7721 90.763 5-8 55.3706 243.98 1-2 76.9690! 471.44 7-8 34.1648 92.886 3-4 55.7633 247.45 5-8 77.3617 476.26 11. 34.5575 95.033 7-8 56.1560 250.95 3-4 '77.7544 1 481.11 1-8 34.9502 97.205 18. 56.5487 254.47 7-8 78.1471 485.98 1-4 35.3429 99.402 1-8 56.9414 258.02 25. 78.5398 490.87 3-8 35.7356 101.62 1-4 57.3341 261 .59 1-8 78.9325 495.79 1-2 36.1283 103.87 3-8 57.7268 265.18 1-4 79.3252 500.74 5-8 36 5210 106.14 1-2 58.1195 268.80 3-8 79.7179 505.71 3-4 36.9137 108.43 5-8 58.5122 272.45 1-2 80.1106 510.71 7-8 37.3064 110.75 3-4 58.9049 276.12 5-8 80.5033 515.72 12. 37 6991 113.10 7-8 59.2976 279.81 3-4 80.8960 520.77 1-8 38.0918 115.47 19. 59.6903 283.53 7-8 81.2887 525.84 1-4 38.4845 117.86 1-8 60.0830 287.27 26. 81.6814 530.93 3-8 38.8772 120.28 1-4 60.4757 291.04 1-8 82.0741 536.05 1-2 39.2699 122.72 3-8 60.8684 294.83 1-4 82.4668 541.19- 5-8 39.6626 125.19 1-2 61.2611 298.65 3-8 82.8595 546.35 3-4 40.0553 127.68 5-8 61.6538 302.49 1-2 aS. 2522 551.55 7-8 40.4480 130.19 3-4 62.0465 3011.35 5-8 83.6449 556.76 13. 40.8407 132.73 7-8 62.4392 310.24 3-4 84.0376 562.00 1-8 41.2334 135.30 20. 62.8319 314.16 7-8 84.4303 567.27 1-4 41.6261 137.89 1-8 63.2246 318.10 27. 84.8230 572.56 3-8 42.0188 140.50 1-4 63.6173 322.06 1-8 85.2157 577.87 1-2 42.4115| 143.14 3-8 64.0100 326.05 1-4 85.6084 583.21 5-8 42.8042 145.80 1-2 64.4026 330. OH 3-8 86.0011 588.57 3-4 43.1969 148.49 5-8 64.7953 334.10 1-2 86.3938 593.96 7-8 43.5896 151.20 3-4 65.1880 338.16 5-8 86.7865! 599.37 14. 43.9823 153.94 7-8 65.5807 342.25 3-4 87.1792; 604.81 1-8 44.3750 156.70 21. 65.9734 346.36 7-8 87.5719 610.27 1-4 44.1677 159.48 1-8 66.3661 350.50 28. 87.9646 615.75 3-8 45.1604 162.30 1-4 66.7588 354.66 1-8 88.35731 6 1.26 1-2 45.5531 165.13 3-8 67.1515 358.84 1-4 88.7500 626.80 5-8 4*5.9458 167.99 1-2 67.5442 3(53.05 3-8 89.1427 632.36 3-4 46.3385 170.87 5-8 67.9369 367.28 1-2 89.5354 637.94 7-8 46.7312 173.78 3-4 68.3296 371.54 5-8 89.9281 643.55 15. 47.1239 176.71 7-8 68.7223 375. A3 3-4 90.3208' 649.18 1-8 47.5166 179.67 22. 69.1150! 380.13 7-8 90.7135j 654.84 1-4 47.9093 182.65 1-8 69.5077 384.46 29. 91.10621 660.52 3-8 48.3020 185.66 1-4 69.9004 388.82 1-8 91.4989 666.23 1-2 48.6947 188.69 3-8 70.2931 393.20 1-4 91.8916' 671.96 5-8 49.0874 191.75 1-2 70.6858 397.61 3-8 92.2843 677.71 3-4 49.4801 194.83 5-8 71.0785 402.04 1-2 92.6770 683.49 7-8 49.8728 197.93 3-4 71.4712 406.49 5-8 93.0697 689.30 16. 50.2655 201.06 7-8 71.8889 410.97 34 93.4624 695.13 1-8 50.6582 204.22 23. 72.2566 415.48 7-8 93.8551 700.98 1-4 51.0509 207.39 1-8 72.6493 420.00 30. 94.2478 706.86 3-8 51.4436 210.60 1-4 73.0420 424.56 18 94.6405 712.76 1-2 51.8363 213.82 3-8 73.4347 429.13 1-4 95.0332 718.69 5-8 52.2290 217.08 1-2 73.8274 433.74 3-8 95.4259 724.64 180 AREAS AND CIRCUMFERENCES OF CIRCLES. TABLE OF CIRCLES Continued. DlAM. INS. CIR- CUMF. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. DlAM. INS. CIR- CTJMF. INS. ARE*. SQ. INS. 30 1-2 95.8186 730.62 37 3-8 117.417 1097.1 44 1-4 139.015 1537.9 5-8 96.21131 736.62 1-2 117.810 1104.5 3-8 139.408 1546.6 3-4 96.6040 742.64 5-8 118.202 1111.8 1-2 139.801 1555.3 7-8 96.9967 748.69 3-4 118.596 1119.2 5-8 140.194 1564.0 31. 97.3894! 754 .-77 7-8 118.988 1126.7 3-4 140.586 1572.8 18 97.7821 760.87 38. 119.381 1134.1 7-8 140.979 1581.6 1-4 98.1748 766.99 1-8 119.773 1141.6 45. 141.372 1590.4 3-8 98.5675 773.14 1-4 120.166 1149.1 1-8 141.764 1599.3 1-2 98.9602 779.31 3-8 120.559 1156.6 1-4 142.157 1608.2 5-8 99.3529 785.51 1-2 1*0.951 1164.2 3-8 142.550 1617.0 3-4 99.7456 791.73 5-8 121.344 1171.7 1-2 142.942 1626.0 7-8 100.138 797.98 3-4 121.737 1179.3 5-8 143.335 1634.9 32. 100.531 804.25 7-8 122.129 1186.9 3-4 143.728 1643.9 1-8 100.924 810.54 39. 122.522 1194.6 7-8 144.121 1652.9 1-4 101.316 816.86 1-8 122.915 1202.3 46. 144.513 1661.9 3-8 101.709 823.21 1-4 123.308 1210.0 1-8 144.906 1670.9 1-2 102.102 829.58 3-8 123.700 1217.7 1-4 145.299 1680.0 5-8 102.494 835.97 1-2 124.093 1225.4 3-8 145.691 1689.1 3-4 102.887 842.39 5-8 124.486 1233.2 1-2 146.084 1698.2 7-8 103.280 848.83 3-4 124.878 1241.0 5-8 146.477 1707.4 33. 103.673 855.30 7-8 125.271 1248.8 3-4 146.869 1716.5 1-8 104.065 861.79 46. 125.664 1256.6 7-8 147.262 17'25.7 1-4 104.458 868.31 1-8 126.056 1264.5 47. 147.655 1734.9 3-8 104.851 874.85 1-4 126.449 1272 .4 1-8 148.048 1744.2 1-2 105.243 881.41 3-8 126.842 1280.3 1-4 148.440 1753.5 5-8 105.636 888.00 1-2 127.2% 1288.2 3-8 148.8^3 1762.7 3-4 106.029 894.62 5-8 127.627 1296.2 1-2 149.226 1772.1 7-8 106.421 901 .26 f-4 128.020 1S04.2 5-8 149.618 1781.4 34. 106.814 907.92 7-8 128.413 1312.2 3-4 150.011 1790.8 1-8 107.207 914.61 41. 128.805 1320.3 7-8 150.404 1800.1 1-4 107.600 921.32 1-8 129.198 1328.3 48. 150.796 1809.6 3-8 107.992 928.06 1-4 129.591 1336.4 1-8 151.189 1819.0 12 108.385 934.82 3-8 129.993 1344.5 1-4 151.582 1828.5 5-8 108.778 941.61 1-2 130.376 1352.7 3,8 151.975 1837.9 3-4 109.170 948.42 5-8 130.769 1360.8 1-2 152.367 1847.5 7-8 109.563 955.25 34 131.161 1369.0 5-8 152.760 1&57.0 35. 109.956 962.11 7-8 131.554 1377.2 3-4 153.153 1866.5 1-8 110.348 969.00 4ft. 131.947 1385.4 7-8 153.545 1876.1 1-4 110.741 975.91 1-8 132.340 1393.7 49. 153.938 1885.7 3-8 111.134 982.84 1-4 132.732 1402.0 1-8 154.881 1895.4 1-2 111.527 989.80 3-8 133.125 1410.3 1-4 154.723 1905.0 5-8 111.919 996.78 1-2 133.518 1418.6 3-8 155.116 1914.7 3-4 112.312 1003.8 5-8 133.910 1427.0 1-2 155.509 1924.4 7-8 112.705 1010.8 3-4 134.303 1435.4 5-8 155.902 1934.2 36. 113.097 1017.9 7-8 134. K96 1443.8 3-4 156.294 1943.9 1-8 113.490 1025.0 43. 135.088 1452.2 7-8 156.687 1953.7 1-4 113.883 1032.1 1-8 135.481 1460.7 50. 157.080 1963.5 3-8 114.275 1039.2 1-4 135.874 1469.1 1-8 157.472 1W3.3 1-2 114.668 1046.3 3-8 136.267 1477.6 , 1-4 157.865 1983.2 5-8 115.061 1053.5 1-2 136.659 1486.2 3-8 158.258 1993.1 3-4 115.454 1060.7 5-8 137.052 1494.7 1-2 158.650 2003.0 7-8 115.846 1068.0 3-4 137.445 1503.3 5-8 159.043 2012.9 37. 116.239 1075.2 7-8 137.837 1511.9 3-4 159.436 2022.8 1-8 116.632 1082.5 44. 138.230 1520.5 7-8 159.829 2032.8 1-4 117.024 1089.8 1-8 138.623 1529.2 51. 160.221 2042.8 ABEAS AND CIRCUMFERENCES OF CIRCLES. 181 TABLE OF CIRCLES Continued. DlAM. INS. ClR- CUMP. INS. ARKA. SQ. INS. DlAM. INS. CIR- CUMF. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. 51 1-8 160.614 2052.8 58. 182.212 2642.1 64 7-8 203.811 3305.6 1-4 161.007 2062.9 1-8 182.605 2653.5 65. 204.204 3318.3 3-8 161.399 2073.0 1-4 182.998 2664.9 1-8 204.596 3331.1 1-2 161.792 2083.1 3-8 183.390 2676.4 1-4 204.989 3343.9 5-8 162.18-. 2093.2 1-2 183.783 2687.8 3-8 205.382 3356.7 3-4 162.577 2103.3 5-8 184.176 2699.3 1-2 205.774 3369.6 7-8 162.970 2113.5 3-4 184.569 2710.9 5-8 206.167 3382.4 52. 163.363 2123.7 7-8 184.961 2722.4 3-4 206.560 3395.3 1-8 163.756 2133.9 59. 185.354 2734.0 7-8 2- 6.952 3408.2 1-4 164. 14S 2144.2 1-8 185.747 2745.6 66. 207.345 3421.2 3-8 164.541 2154.5 1-4 186.139 2757.2 1-8 207.738 3434.2 1-2 164.934 2164.8 3-8 186.532 2768.8 1-4 208.131 3447.2 5-8 165.336 2175.1 1-2 186.925 2780.5 3-8 208.523 3460.2 3-4 165.719 2!85.4 5-8 187.31? 2792.2 1-2 208.916 3473.2 7-8 166.112 2195.8 3-4 187.7KI 2803.9 5-8 209.309 3486.3 53. 166.504 2203.2 7-8 188.103 2815.7 3-4 209.701 3499.4 1-8 166.897 2216.6 60. 188.496 2827.4 7-8 210. ('94 a512.5 1-4 167.290 2227.0 1-8 188.888 2839.2 67. 210.487 3525.7 3-8 167.683 2237.5 1-4 189.281 2851.0 1-8 210.879 b538.8 1-2 168.075 2248.0 3-8 189 674 2862.9 1-4 211.272 3552.0 5-8 168.468 2253.5 1-2 190.066 2874.8 3-8 211.665 a565.2 3-4 168.861 22(39.1 5-8 191.459 2S86.6 1-2 212.058 3578.5 7-8 169.253 2279.6 3-4 190.852 2898.6 5-8 212.450 3.391.7 54. 169.646 2290 2 7-8 191.244 2910.5 3-4 212.843 3605.0 1-8 170.039 2300.8 61. 191.6*7 2922.5 7-8 213.236 3618.3 1-4 170.431 2311.5 1-8 192.030 2934.5 68. 213.628 3631.7 3-8 170.824 2322.1 1-4 192.423 2916.5 1-8 214.021 3645.0 1-2 171.217 2332.8 3-8 192.815 2958.5 1-4 214.414 3658.4 5-8 171.609 2343.5 1-2 193. 20s 2970.6 3-8 214.806 3671.8 3-4 172.002 2354.3 5-8 193.601 2982.7 1-2 215.199 3685.3 7-8 172. &95 2365.0 3-4 193.993 5994. 8 5-8 215.592 3698.7 55. 172.788 2375.8 7-8 194.388 3006 9 3-4 215.984 3712.2 1-8 173.180 2386.6 62. 194.779 3(119.1 7-8 216.377 3725.7 1-4 173.573 2397.5 1-8 195.171 3031.3 69. 216.770 3789.3 3-8 173.966 2108.3 1-4 195.564 3043.5 1-8 217. 163 3752.8 1-2 174.358 2419.2 3-8 195.957 3055.7 1-4 217.555 3766.4 5-8 174.751 24:30.1 1-2 196.350 3068.0 38 217.948 3780.0 3-4 175.144 2441 .1 5-8 196.742 3080.3 1-2 218.341 3793.7 7-8 175.536 2452.0 3-4 197.135 3092.6 5-8 218.733 3807.3 56. 175.929 2463.0 7-8 197.528 3104.9 3-4 219.126 3821.0 1-8 176.3-22 2474.0 63. 197.920 3117.2 7-8 219.519 3834.7 1-4 176.715 2485.0 1-8 198.313 3129.6 70. 219.911 3H48.5 3-8 177.107 2496.1 1-4 198.706 3142.0 1-8 220.304 3862.2 1-2 177.500 2507.2 3-8 199.098 3154.5 1-4 220.697 3876.0 5-8 177.893 2518.3 1-2 199.491 3166.9 3-8 221.000 3889.8 3-4 178.285 2529.4 5-8 199.884 3179.4 1-2 221.482 3903.6 7-8 178.678 2540.6 3-4 200.277 3191.9 5-8 221.875 3917.5 57. 179.071 2551.8 7-8 200.669 3204.4 3-4 222.268 3931.4 1-8 179.463 2563.0 61. 201.062 3-217.0 7-8 222.660 3945.3 1-4 179.856 2574.2 1-8 201.455 3229.6 71. 223.053 3959.2 3-8 180.249 2585.4 1-4 201.847 3242.2 1-8 223.446 3973.1 1-2 180.642 2596.7 3-8 202.240 3254.8 1-4 223.838 3987.1 5-8 181 .034 2608.0 1-2 202.633 3267.5 3-8 224.231 4001.1 3-4 181.427 2619.4 5-8 203.025 3280.1 1-2 224.624 4015.2 7-8 181.820 2630.7 3-4 203.418 3292.8 5-8 225.017 4029.2 182 AREAS AND CIRCUMFERENCES OF CIRCLES. TABLE OF CIRCLES Continued. DlAM. INS. ClB- CUMP. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMP. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. 713-4 225.409 4043.3 78 5-8 247.008 4855.2 85 1-2 268.606 5741.5 7-8 225.802 4057.4 3-4 247.400 4870.7 5-8 268.999 5758.3 72. 226.195 4071.5 7-8 247.793 4886.2 3-4 269.392 5775.1 1-8 226.587 4085.7 79. 248.186 4901.7 7-8 269.784 5791 .9 1-4 226.980 4099.8 1-8 248.579 4917.2 86. 270.177 5808.8 3-8 227.373 4114.0 1-4 248.971 4932.7 1-8 270.570 5825.7 1-2 227.765 4128.2 3-8 249.364 4948.3 1-4 270.962 5842.6 5-8 228.158 4142.5 1-2 249.757 4963.9 3-8 271.1355 5859.6 3-4 828.551 4156.8 5-8 250.149 4979.5 1-2 271.748 5876.5 7-8 228 9441 4171.1 3-4 250.542 4995.2 5-8 272.140 5893.5 73. 229. a36 4185.4 7-8 250.935! 5010.9 3-4 272.533 5910.6 1-8 229.729 4199.7 80. 251. 327 i 5026.5 7-8 272.926 5927.6 1-4 230.122 4214.1 1-8 25l.720| 5042.3 87. 273.319 5944.7 3-8 230.514 4228.5 1-4 252.113 5058.0 1-8 273.711 5961.8 1-2 230.907 4242.9 3-8 252.506 5073.8 1-4 274.104 5978.9 5-8 231.300 4257.4 1-2 252.898 5089.6 3-8 274.497 5996.0 3-4 231.692 4271.8 5-8 253.291 5105.4 1-2 274.889 6013.2 7-8 232.085 4286.3 3-4 253.684 5121.2 5-8 275.282 6030.4 74. 232.478 4300.8 7-8 254.076 5137.1 3-4 275.675 6047.6 1-8 232.871 4315.4 81. 254.469 5153.0 7-8 276.067 6064.9 1-4 233 263 4329.9 1-8 254.862 5168.9 88. 276.460 6082.1 3-8 233.656 4:i44.5 1-4 255.254 5184.9 1-8 276.853! 6099.4 1-2 234.049 4359.2 3-8 255.647 5200.8 1-4 277.246! 6116.7 5-8 234.441 4373.8 1-2 256.0401 5216.8 3-8 277.638 6134.1 3-4 234.834 4388.5 5-8 256.433! 5232.8 1-2 278.031 6151.4 7-8 235.2271 4403.1 3-4 256.8251 5248.9 5-8 278.424 6168.8 75. 235.619 4417.9 7-8 257.218! 5264.9 3-4 278.816 6186.2 1-8 236.012 4432.6 82. 257.6111 5281.0 7-8 279.209 6203.7 1-4 236.405 4447.4 1-8 258.003 5297.1 89. 279.602 6221.1 3-8 236.798 4462.2 1-4 258.396 5313.3 1-8 279.994 6238.6 1-2 237.190| 4477.0 3-8 258.789 5329.4 1-4 280.387 6256.1 5-8 237.583! 4491.8 1-2 259.181 5345.6 3-8 280.780 6273.7 3-4 237.976! 4506.7 5-8 259.574 5361.8 1-2 281.173 6291.2 7-8 238.368 4521.5 3-4 259.967 5378.1 5-8 281.565 6308.8 76. 2:.761 4536.5 7-8 260.359 5394.3 3-4 281.958 6326.4 1-8 239.154 4551.4 83. 260.752 5410.6 7-8 282.351 6344.1 1-4 239.546 4566.4 1-8 261.145 5426.9 90. 282.743 6361.7 3-8 239.939 4581.3 1-4 261.538 5443.3 1-8 283.136 6379.4 1-2 240.332 4596.3 3-8 261.930 5459.6 1-4 283.529 6397.1 5-8 240.725 4611.4 1-2 262.323 5476.0 3-8 283.921 6414.9 3-4 241.1171 4626.4 5-8 262.716 5492.4 1-2 284.314 6432.6 7-8 241.510! 4641.5 3-4 263.108 5508.8 5-8 284.707 6450.4 77. 241.903: 4656.6 7-8 263.501 5525.3 3-4 285.100 6468.2 1-8 242.295J 4671.8 84. 263.894 5541 .8 7-8 285.492 6486.0 1-4 242.688 4686.9 1-8 264.286 5558.3 91. 285.885 6503.9 3-8 243.081 4702.1 1-4 264.679 5574.8 1-8 286.278 6521.8 1-2 243.473 4717.3 3-8 265.072 5591.4 1-4 286.670 6539.7 5-8 243.866: 4732.5 1-2 265.465 5K07.9 3-8 287.063 6557.6 3-4 244.259! 4747.8 5-8 265.857 5K24.5 1-2 287.456 6575.5 7-8 244.652 4763.1 3-4 266.250 5641.2 5-8 287.848 6593.5 78. 245.044! 4778.4 7-8 266.643 5657.8 3-4 288.241 6611.5 1-8 245.437 4798.7 85. 267.035 5674.5 7-8 288. 634 6(i29.6 1-4 245.830 4809.0 1-8 267.428 5691.2 92. 289.027 6647.6 3-8 246.222 4824.4 14 267.821 5707.9 1-8 289.419 6665.7 1-2 246.615 4839.8 3-8 268.213 5724.7 1-4 289.812 6683.8 AKEAS AND CIKCUMFERENCES OF CIECLES. 183 TABLE OF CIRCLES Continued. DlAM. INS. ClR- CUMF. INS. AREA. SQ. INS. DlAM. INS. ClR- CUMF. INS. ABE A. SQ. INS. DlAM. INS. Cm- CUMF. INS. A"KA. SQ. INS. 92 3-8 290.205 6701.9 95. 298.451 7088.2 97 5-8 306.698 7485.8 1-2 290.597 6720.1 1-8 298.844 7106.9 3-4 307.091 7504.5 5-8 290.990 6738.2 1-4 299.237 7125.6 7-8 807.468 7523.7 3-4 291.383 6756.4 3-8 299,629 7144.3 98. 307.876 7543.0 7-8 291.775 6774.7 1-2 300.022 716::. 1-8 308.269 7562.2 93. 292.168 6792.9 5-8 300.415 7181.8 1-4 308.661 7581.5 1-8 292.561 6811.2 3-4 800.807 7-J00.6 3-8 309.054 7600.8 1-4 292.954 6829.5 7-8 301. 200 : 7219.4 1-2 309.447 7620.1 3-8 293.346 6847.8 96. 301.593 7238.2 5-8 809.840 7639.5 1-2 293.739 6866.1 1-8 301.986 7257.1 3-4 310.232 7658.9 5-8 294.132 6884.5 1-4 302.3781 7276.0 7-8 310.625 7678.3 3-4 294.524 6902.9 3-8 302.771 7294.9 199. 311.018 7697.7 7-8 294.917 6921.3 1-2 303.1 64 7313.8 1-8 311.410 7717.1 M. 295.310 6939.8 5-8 303.556- 7332.8 1-4 311.803! 7736.6 1-8 295.702 6958.2 3-4 303.949 7351.8 3-8 312.1961 7756.1 1-4 29(5.095 6976.7 7-8 304.342 7370.8 1-2 312.588 7775 6 3-8 296.488 691)5.3 97. 304.734 7389.8 5-8 312.981J 7795.2 1-2 296.881 7013.8 1-8 305.127 7408.9 3-4 313.374 7814.8 5-8 297.273 7082.4 1-4 305.520 7428.0 7-8 313.767| 7834.4 3-4 297.666 7051.0 3-8 305.913 7447.1 100. 314.159 7854.0 7-8 298.059 7069.6 1-2 306.305 7466.2 184 WEIGHT OF ROLLED IEON. WEIGHT OF A LINEAL FOOT OF ROUND AND SQUAKlS IRON. SIZE IN INCHES. BOUNDS. SQUARES. SIZE IN j INCHES. ROUNDS. SQUARES. WEIGHT PER FOOT. WEIGHT PER FOOT. WEIGHT PER FOOT. WEIGHT PER FOOT. & 0.01 0.013 3f 29.82 37.969 JL 0.041 0.052 3a 32.07 40.833 A 0.092 0.117 *| 34.40 43.802 i 0.163 0.208 3* 36.813 46.875 i 0.363 0.468 31 39.31 50.052 0.654 0.833 4* 41.887 53.333 & 1.023 1.302 4* 44.547 56 719 f 1.472 1.875 4} 47.287 GO. 208 2.004 2.552 41 50.11 63.802 i 2.618 3.333 41 53.013 67.50 H 3.313 4.218 4 f 56.00 71.302 U 4.09 5.208 59.057 75.208 U 4.947 6.302 4 62.217 79.219 H 5.89 7.50 5 65.45 83.333 if 6.01 8.802 51 68.763 87.552 11 8.017 10.208 8 72.157 91.875 11 9.203 11.718 5f 75.633 96.302 2 10.47 13.333 5 1 79.197 100.833 3| 11.82 15.052 ' 5 f 82.833 105.468 2V 13.253 16.875 86.557 110.208 21 14.766 18.803 5| 90.36 115.052 3* 16.36 20.833 6 94.247 120.00 81 18.036 22.969 (ji 102.263 130.208 19.797 25.208 6^ 110.61 140.833 3 23.56 30.00 6| 119.28 151.875 3i 25.563 32.552 7 128.28 163.333 51 27.65 35.208 WEIGHT OF KOLLED IRON. 185 WEIGHT OF A LINEAL FOOT OF FLAT IRON. | Width in Inches. 1 THICKNESS IN INCHES. A 8 * i ft 1 * * SL 1 I 8 1 i 0.16 0.31 0.47 0.63 0.77 0.94 1.09 1.25 1.56 1.8* 2.18 2.50 JO. 18 0.360.55 0.73 0.91 1.09 1.28 1.46 1.83 2.19 2.5b 2.92 1 0.210.420.62 H 0.23(0.47,0.70 0.83 0.94 1.04 1.17 1.25 1.41 1.46 1.64 1.67 1.68 2. 08 2.34 2.50 2.81 2.92 3.28 3.33 3.75 HO. 26 0.520.78 1.04 1.30 1.56 1.82 2.08 2.60 3.12 3.64 4.17 10.29 0.57 0.86 1.15 1.43 1.72 2.00 2.29 2.86 3.44 4.01 4.58 HO. 31 0.630.94 1.25 1.56 1.88 2.19 2.50 3.13 3.75 4.38 5.00 110.34 0.681.02 1.35 1.69 2.03 2.37 2.71 3.38 4.06 4.74 5.42 HO. 36 0.73 1.09 1.46 1.82 2.19 2.55 2.92 3.65 4.37 5.10 5.83 If 0.39 0.78 1.17 1.56 1.95 2.34 2.73 3.12 3.91 4.68 5.46 6.25 2 0.42 0.83 1.24 1.67 2.08 2.50 2.92 3.33 4.17 5.00 5. as 6.67 2^0.44 0.89 1.33 1.77 2.21 2.66 3.10 3.54 4.43 5.31 6.20 7.C8 2i0.47 0.94 1.41 1.88 2.34 2.81 3.28 3.75 4.69 5.63 6.56 7.50 2f 0.49 0.991.48 1.98 2.47 2.96 3.46 3.96 4.95 5.94 6.93 7.92 2J0.52 1.041.56 2.08 2.60 3.12 3.64 4.17 5.21 6.25 7.29 8.33 2|0.55 1.091.64 2.19 2.73 3.2S 3.83 4.38 5.47 6.56 7.66 8.75 2f 0.57 1.141.72 2.29 2.86 3.44 4.01 4.59 5.73 6.87 8.02 9.17 2J0.60 1.201.80 2.40 2.99 3.59 4.19 4.79 5.99 7.19 8.38 9.58 3 0.62 1.251.87 2.50 3.12 3.75 4.37 5.00 6.25 7.50 8.75 10.00 3f0.68 1.352.03 2.71 3.38 4.07 4.74 5.42 6.77 8.12 9.48 10.83 3i0.73 1.462.19 2.92 3.65 4.38 5.11 5.83 7.29 8.75 10.21 11.67 3f 0.78 1.562.34 3.12 3.90 4.69 5.47 6.25 7.81 9.37 10.94 12.50 4 0.83 1.672.50 3.33 4.17 5.00 5.83 6.67 8.33 10.00 11.67 13.33 4*0.94 1.872.81 3.75 4.69 5.63 6.56 7.50 9.38 11.25 13.13 15.00 5 1.04 2.083.13 4.17 5.21 6.251 7.30 8.34 10.42 12.50 14.59 10.67 6 1.25 2.503.75 5.00 6.25 7.50 8.75 10.00 12.50 15.00 17.50 20.00 7 1.46 2.924.37 5.83 7.29 8.75 10.20 11.67 14.58 17.50 20.42 23.33 8 1.67 3.335.00 6.67 8.34 10.00 11.67 13.33 16.67 20.00 23.33 26.67 9 1.87 3.755.62 7.50 9.37 11.25 13.12 15.00 18.75 22.50 26.25 30.00 102.08 4.176.25 8.33 10.42 12.50 14.58 16.67 20.83 25.00 29.17 33.33 11 2.29 4.586.87 9.17 11.46 13.75 16.04 18.33 22.92 27.50 32.08 36.67 12J2.50 5.007.50 10.00 12.50 15.00 17.50 20.00 25.00 30.00 35.00 40.00 186 DECIMAL EQUIVALENTS FOB FRACTIONS. DECIMAL EQUIVALENTS FOR FRACTIONS OF AN INCH. FRACTION. DECIMAL. FRACTION. DECIMAL. * .015625 33. .515625 .03125 |l .53125 ft .046875 H .546875 5s .0625 ft .5625 A .078125 11 .578125 .09375 l .59375 ft .109375 II .609375 j_ 9 .125 1 .625 J .140625 AL .640625 i .15625 .171875 II '. 671875 .1875 !i .6875 .203125 fl .703125 .21875 ^.a. .71875 .234375 il .734375 * .25 4 .75 tt .265625 h4 .765625 V .28125 .78125 32" .296875 ^1 .796875 5 .3125 ft .8125 ti .328125 f! .828125 XI .34375 21 .84375 II .359375 64* .859375 f .375 M 1 .875 2/L .390625 H .890625 1 | .40625 ft .90625 li .421875 .921875 ?y .4375 11 .9375 ^a .453125 H .953125 Vs .46875 31. .96875 fi .484375 It .984375 .5 STANDARD SEPARATORS FOR PENCOYD BEAMS. 187 STANDARD SEPARATORS FOR PENCOYD I BEAMS. CHART No. SIZE OF BEAM. Weieht of separator. JS -S 5 K^ s* ill jr-s BOLTS, A. Weight of each complete bolt. jjf No. SIZE. 1 15 " Heavy 22 3.84 2 r 1.75 .123 2 15 " Light 21 3.13 2 3." 1.62 .123 3 12 " Heavy 16 2.76 2 " 1.69 .123 4 12 " Light 14? 2.95 2 li" 4 1.58 .123 5 10" Heavy in 2.10 1 3." 4 1.64 .123 51 lO.f" Medium 11 2.06 1 2" 4 1.28 .123 6 10|" Light 11 2.03 1 1" 1.53 .123 7 10 " Heavy 10 1.93 1 " 4 1.56 .123 8 10 " Light 10 1.93 1 r 1.52 .123 9 3$: All weights iven in pounds perYard. Plate Nn. .5 Wt. 112 tn 137. Lbs. S Nn.7 Wt. BD to !D6Lbs. H? Nn. B All weights iven in pounds perYard. -;v W - ..*! Plate Nc. B Wt.34 tn 4DLhs. Wt.3D tn 4D Lhs. pp Nn.!7 Na. IB Wt.eD fn 22 Lhs. Wt. 7D tn BB Lhs. ND. a 05 N D. I D All weights ^iven in pounds perYard. Plate Ha. 7 Wt..5d tn B3 Lhs. Wt. 4D to E3 Lhs. NnlS * Nn.lB < 3% - <- 3*-~ -> Wt.Bl tn IDB.3 Lbs: Wl.'BS tn 75 Lhs. Nn.ll & 00 N a. 1 2 All weights ^iven in pounds pet: Yard. Flats Nn. B Nnl3 WtBS to BB Lbs. Wt.Sl to BB Lbs, Nn.13 NaZD Wt. 28 ta 38 Lbs, Wt-IS.S tp 2I.S Lbs. -sty All weights ^iven in pounds pei:Yard. Plate Nn. H ND. 3D h Nn.33 in in J3 a LG All weights ^iven in pounds perYard. Plate Nn. ID No. 32 Nn.3I All weights ivEn in pounds perYard. Plate No. I! All weights ^iven in pounds perYard. '3 2 Plate No. 12 Nn. 36 Nn. 37 B I Nn. 38 Wt. 43 tn BD.5 Lbs, Nn. 3 3 Wt. 3D tn 54 Lhs. ff All weights ^iven in pounds perYard. Plate Nn.13 Plate Nn. 2 All weights iven in pounds perYard. Plate Nn.lS All weights iven in pounds perYard. Plate Na.lB Na.E4 No.ES m ra No, B7 "in DJ No.GB 3% All weights ^iven in pounds perYard. Plate NQ. 17 Wt.3.fi.5 Lbs. 4" Wt.3 Lbs. No.7D Wt.3 Lbs. * No.71 Wt. ZE.Lbs. $>.... ND.BI Wt.ia.5 Lhs. '-,-- -2% 1%'~~ Nn.72 ND.BD Na.73 Wt.17. 52 Lhs. Wt.B Lhs. Wt.11.7S Us. - " 5 Nn.75 Wt.IZ Lhs. Wt.7.I Lhs. NnJB NnJB Wt.lD.S Lbs. o Nn.77 All weights &\ven in pounds perYard. Plate Nn. IB Wt. ZZ-.E Lbs. ~ r^n ' *I * " ! ND.B3 Wt.19.3 Lbs. Na.BZ All weights ^iven in pounds perYard. Plate Nn.lS Wt. 44. I Lhs. Wt.2D..4Lfas. IS/' 3**V Np.lDY ^ tv _, Wt. 48,^44 Lbs, I ^ . fc* J xr- % - ,- Nn .IDE Wt.11.2 Lbs, J* ^ 1 Nn.9B Wt.2&.2SLhs. Na.37 Wt.23.7S Lhs. Wt.lB.7SLhs. Wt. 21. Lhs. ------- 2%-- Nn.lD4 NQ. ins All weights ^iven in pounds perYard. Plate ND. 2D Wt.44-S Lhs. Wt.4LB Lhs. Nn.an Wt.7 Lhs. Wt.3.1 Lhs. Wt. 3D. 7 Lhs.. Wt.B ; 7SLhs. Nn.92 <_ ...... -2' ..... --> Wt. 33. Lhs. ----- J* Nn.lD3 Wt.25.H Lhs. No. 94 Wt.ZS.ZS Lhs. Nn.95 i_._.J All weights ivEn in pounds perYard. Pi ate No. 21 Wt.38.5 Lhs. --4' Wt.ZD.B Lbs. 15*4 Nn.lll No.ina Wt. 17.7 Lbs. All weights ^iven in pounds perYard. Plate Nn.ZS Na.l2Q No. 129 Na.132 ^L\ AH weights ^iven in pounds perYard. Plate Nn.23 Nal54 Nn.152 No.l4D NfclSt Na.153 Na. 141 Na.142 Ka.143 All weights ^iven in pounds perYard. Plate ND. 2-q- Na.lSD ND.I5S Nn.lSB Nn.I57 All weights ^iven in pounds perYard. Plate ND. NQ.IHD Nn.171 Alt weights ivEn in pounds perYard. Plate Nn.ZB Nn.lBD Nn.lBI Nn.lB2 Nn.lB3 All weights ^iven in paunds perYard. Plate No. 2 7 Nn.lBl WtS.2Lba Nn.190 Wt.ZS Lbs, Wt.SB L-hs ' No. 192 No. 134. Nn.lB3. * Wt.4.3 Lhs.p. Y2rd. Wt 4.3 Lhs. p. Yard. Nn 135 5 ND. me Nn. 197 No. 19B ' 2D,a tn 34.5 Lbs. All weights ^iven in pounds perYard. Plate No. 28 METHOD OF INCREASING SECTIONAL AREAS. Cross-hatched portions represent the minimum sections, and the blank portions the added areas. W, All weights ivEn in pounds perYard. RETURN TO MAIN CIRCULATION ALL BOOKS ARE SUBJECT TO RECALL RENEW BOOKS BY CALLING 642-3405 DUE AS STAMPED BELOW MAR 07 1996 RECEJV^D DEC ? ' or ^IRCULATiO 11 ' i t/tf/"t FORM NO. DD6 UNIVERSITY OF CALIFORNIA, BE BERKELEY, CA 94720 U. C. BERKELEY LIBRARIES fJT06585